Declension System of Latin Nouns

Latin nouns are as difficult as Latin verbs.  Corresponding to its grammatical function in a sentence, a Latin noun must change its ending and maintain consistency of its ending. 

Five Major Grammatical Roles

In any language, a noun can assume various grammatical roles in a sentence.  In Latin, five different grammatical roles can be played by a noun and they are:  nominative, genitive, dative, accusative, and ablative.  What are they?  Well, we are now going to describe each of them to make us confused no more by so called declension system of Latin nouns. 

1. When a noun is used as a subject of a sentence, we say that this noun is nominative.  Of course, the predicate of linking verbs (such as “to be” and “to seem”) is used to describe the subject in a sentence and hence considered to have a grammatical parity with the subject.  For this reason, if a noun is used as the predicate of a linking verb, it is also considered nominative and is called predicate nominative.  “Nominative” simply indicates that a noun is used as a name.

2. Sometimes, a noun is is used to specify a grammatical possessiveness, such as father’s son (or son of a father).  Note, I used the term grammatical possessiveness to include some dependent relationship as “a lot of money”, which has nothing to do with a physical possession.  When a noun is used to express such a possessive relation in a format of “father’s son”, not in a format of prepositional phrase as “a son of father”, it plays a genitive role. genitive is from Latin “genitivus”, indicating the source of origin and belonging (where to come from). 

3. The term "dative” carries the meaning of “giving” or “giving to” and it is itself from the Latin word “dativus”.  As we know, a transitive verb must have an object, for instance, in the sentence “I love the girl”, “girl” is the object of verb “love” and it (here, she) receives action of this verb (loving).  However, sometimes a verb has more than one object, as verb may have a receiver and a target of its action.  In the sentence “I give the girl money”,  “money” is the receiver (to be given) and “girl” is the target (given to).  The receiver of action (what’s being done) is called direct object and the target of action (to whom/what it is done) is called indirect object.  When a noun is used as an indirect verb object, we say that the noun is dative.  In many occasions, even linking verbs can have a target.  “She was not nice” has no explicit target (may have an implied one), but “She was not nice to me” has a target and “to me” is expressed in Latin by the dative “me”. 

4. “accusative”?  Think of  “accuse = bring charges against” when you see “accusative”.  In a grammatical sense, the object being charged is just the object of a transitive verb.  Therefore, accusative case of a noun simply indicates the noun being used as a direct object of a transitive verb in a sentence.  Manytimes, an accusative noun is also used as an object of a preposition.

5. “ablative” is from the Latin word “ablatus”, meaning carrying.  In the grammatical sense, the ablative case of noun implies that the noun is used as a carrier.  What carrier?  A carrier of a verb action.  For instance, in “She kills me with a knife”, “knife” is the carrier of the verb action “killing”.  In English, we must use a prepositional phrase to express such a verb carrier (means and ways, by who or by what, to modify verbs), but in Latin, an ablative noun with a proper ending can do it and the prepositional phrase won’t be necessary sometimes.  It’s just like a noun used to modify a verb.

In Latin grammar, there are also vocative and locative cases to indicate to whom the sentence is addressed to (vocative) and where is verb action takes place (locative).  But I’ll show my mercy to give you a break by skipping these last two not often used cases. 

Meanings of Noun Declension

To show which grammatical function a noun takes in a sentence, Latin people added different endings to the base form of a noun.  For instance, puell- is the base form for  English word “girl”.  If it is a singular girl, pretty or ugly, old or young, then puella is the nominative, puellae is the genitive, puellae is also the dative, puellam is the accusative, and puellā is the ablative.  If it is plural (many girls), then puellae is the nominative, puellārūm is the genitive, puellīs is the dative, puellās is the accusative, and puellīs is the ablative.   

Such a narrative to describe ending variation demonstrating a noun’s grammatical role is cumbersome and so Latin people like to customarily write (or list) down such ending changes as follows:

      Table One  Base form: puell-

            Singular ending   Plural  ending

Nom.  puella  -a    puellae  -ae

Gen.  puellae  -ae   puellārūm -ārūm

Dat.  puellae  -ae   puellīs  -īs

Acc.  puellam -am   puellās  -ās

Abl.  puellā  -ā   puellīs  -īs

The mission for you, a student of Latin, is to remember the set of endings for each declension group and to know which ending to add to a particular noun for its particular grammatical function in a particular sentence.  However, the difficulty is that the same ending such as –ae and –īs represent difference grammatical roles.  The only way to overcome this is to sharpen your understanding and  judgment in the context through innumerous and ruthless practice.  The ancient Latin people did it, and we can do it, too, assuming a modern human being has a larger skull than his or her ancestor living hundred years ago. 

In this format, Latin people listed all grammatical endings for both singular and plural forms of a noun, from top to bottom, in a descending order of nominative, genitive, dative, accusative, and ablative.  They named it “grammatical case” of a noun.  Do you ever know the original meaning of the English word “case”?  It means “falling from top to bottom”¹.  Grammatically, the way to list endings for a Latin noun is call “declension of a noun”.  The verb of declension is “to decline (to fall from top to bottom)” and in a Latin class you will be asked to decline a noun a gazillion of times.  That is why you often hear people talk about a Latin noun with its five cases.  Hope this bit of historical aroma would help you understand and remember Latin nouns better. 

Now we know that a noun performs one the five grammatical functions.  However, the historical Latin people, either super intelligent or dumbest, categorized nouns into five groups, to further complicate Latin noun phenomena.  Oh, please do not hate them yet, since it is only the tip of the iceberg of Latin nouns².  The criterion they used to categorize nouns is the nominative singular ending.  For instance, all the nouns with the nominative singular ending –a belong to the first group of nouns called “first declension group”³.   

Five Declensions and Genders of Latin Nouns

There are five of them:  first declension, second declension, third declension, fourth declension, and fifth declension.  To make it even worse, Latin people believe that each noun has a gender, even if it is a road.  So a noun must be either male or female or neither male nor female.  For instance, they believed that a rood (via) is female, while a river (flūvius) is male, while a war (bellum) is neuter.  Absurd, isn’t it, but that’s the way Latin is.  In grammatical terms, a noun can be masculine (male), or feminine (female), or neuter (neither male nor female).   

First Declension

As said before, all the nouns with a nominative singular ending –a belong to this group.  Nouns in the first declension group are almost all feminine.  “almost” means that there are some exceptions.  The exceptions you need to remember at this point are:

            agricola, masculine, meaning a farmer.

            incola, masculine, meaning an inhabitant.

            nauta, masculine, meaning a sailor.

            poeta, masculine, meaning a poet⁴.

We have already learned how to decline a first declension noun for puella.  To further sharpen your declining skills, let’s try another one:  fēmina⁵ (= lady).  It is feminine and its base form is fēmin-.

      Table Two:  Base Form⁶: fēmin-

            Singular ending   Plural   ending

Nom.   fēmina  -a   fēminae -ae

Gen.  fēminae -ae   fēminārūm -ārūm

Dat.  fēminae -ae   fēminīs  -īs

Acc.  fēminam -am   fēminās -ās

Abl.  fēminā  -ā   fēminīs  -īs 

Next, try a masculine first declension noun:  agricola (m. short for masculine) = farmer

      Table Three:  Base Form: agricol-

            Singular ending   Plural   ending

Nom.   agricola -a   agricolae  -ae

Gen.  agricolae  -ae   agricolārūm -ārūm

Dat.  agricolae -ae   agricolīs -īs

Acc.  agricolam -am   agricolās -ās

Abl.  agricolā -ā   agricolīs -īs 

Practice of declining hundreds of nouns in this group is much needed for you to have a good command of Latin nouns.  Do not skip them and superficially believe that you need only two minutes to remember them.  Without deep practice, you will find your oblivion overpowers your memory so easily. 

Application of First Declension Nouns

Now we provide ourselves a chance to put some of the first declension nouns in sentences and practice our grammatical understand about them.

      Fēminam amō.  =  I love that lady (amō, amāre = love)

      Amāsne fēmina poetam?  = Does the lady love the poet?

In the first sentence, “lady” is the object of verb love and so it takes the accusative case of “fēmina”.  In the second sentence, “fēmina” is the nominative case and so it is used as the subject of this sentence.  “poetam” is the accusative case of “poeta” (right now, ignore Latin verbs for the time being and concentrate on the understanding of Latin nouns and their grammatical functions.  There will be a separate write-up for Latin verbs, too).

      The Latin word for “a lot” is “cōpia”.  It is a feminine first declension noun.  The Latin word for “money” is “pecūnia”, which is also a feminine first declension noun. 

      Puellae cōpiam pecūniae dō.  =  I give the girl a lot of money.

How?  “dō” = I give, which you will learn in my Latin verb pamphlet.  “puellae” could be the nominative plural, or the genitive singular, or the dative singular of “puella”.  What is it really?  Well, let’s look at the other parts first.  “cōpiam” means a lot and it is in the accusative case, which means it is the object of “give”.  “pecūniae”, again, can be the nominative plural, or the genitive singular, or the dative singular of “pecunia”.  Put them together, the only meaningful translation is “I give the girl a lot of money”.  That is to say, in this sentence, “puellae” is the dative singular, indicating it is the indirect object, and “pecūniae” is the genitive singular and “cōpiam pecuniae” = a lot of money.  Does this analysis start to make sense to you now? 

Let’s try one more.  The Latin verb for “he kills” = necat (infinitive: “necāre”).  The Latin word for spear is “hasta” and it is a feminine first declension noun.  Latin word “nauta” means a sailor and Latin word “incola” means an inhabitant.  Both “nauta” and “incola” are masculine first declension nouns. 

      Nauta hastā incolam necat⁷.  =  The sailor kills the inhabitant with a spear⁸.

“Nauta” is in its nominative singular and so it is the subject of this sentence.  “incolam” is the accusative singular of “incola” and so it is the object of “he kills”.  Now “hastā” has a long vowel on the ending “a”, implying that it is the ablative singular of “hasta”.  As discussed before, the ablative case indicates that the noun is used as a means or a way by which the verb action is done.  So the verb action “he kills” is done through a spear.  Putting together, this sentence is translated as “the sailor kills the inhabitant with a spear”.

      As a practice, can you change the singular form for each noun used in the above sentences into its plural, with corresponding endings, and then translate them into English? 

Second Declension:

Nouns in this group has three kinds:  masculine and neuter.  However, not all masculine nouns belong to this group (we have seen some are already in the first declension group).  Only those masculine ones with a nominative singular ending -us belong to this group⁹.

We call this the first subgroup of the second declension group.  Meanwhile, not all neuter nouns belong to this group, either.  Only those neuter ones with a nominative singular ending -um belong to this group.  We call this second subgroup of the second declension group.  There are also some other masculine nouns belonging to the second declension.  They are the masculine ones with a nominative singular ending being either –er or –ir.  We call them the third subgroup of the second declension.  The problem with the second declension is that endings for its three subgroup is not exactly the same. 

First Subgroup of Second Declension

Let’s learn first the endings of the first subgroup.  amicus is such an example.  The English word for amicus is friend.  Now, we decline the noun amicus.

      Table Four:   Base Form:  amic-

            Singular ending   Plural  ending

Nom.  amicus  -us   amicī  -ī

Gen.  amicī  -ī   amicōrūm -ōrūm

Dat.  amicō  -ō   amicīs  -īs

Acc.  amicum -um   amicōs  -ōs

Abl.  amicō  -ō   amicīs  -īs

servus is the masculine Latin word for English slave.  By looking at its ending –us, you probably can tell that it is a noun of the first subgroup of second declension, and it is a nominative singular.  Let’s decline this word as a practice:

      Table Five:   Base Form:  serv-

            Singular ending   Plural  ending

Nom.  servus  -us   servī  -ī

Gen.  servī  -ī   servōrūm -ōrūm

Dat.  servō  -ō   servīs  -īs

Acc.  servum  -um   servōs  -ōs

Abl.  servō  -ō   servīs  -īs 

To deepen your memory, here is a third one, fīlius = son, for you to decline.

      Table Six:   Base Form:  fīli-

            Singular ending   Plural  ending

Nom.  fīlius  -us   fīliī  -ī

Gen.  fīliī  -ī   fīliōrūm -ōrūm

Dat.  fīliō  -ō   fīliīs  -īs

Acc.  fīlium  -um   fīliōs  -ōs

Abl.  fīliō  -ō   fīliīs  -īs 

Applying the First Subgroup of Second Declension

Again, let’s analyze some sentences to iron these endings in your brain. 

      Fīlus fēminae bonus est. = “The son is nice to the lady” or “the lady’s son is nice”

How?  fīlius is the nominative singular, indicating it is the subject.  “est” = he is and bonus = nice/good as an adjective.  fēminae could be the nominative plural, the genitive singular, or dative singular.  When fēminae is interpreted as dative singular, the translation should be “The son is nice to the lady”.  When it is interpreted as genitive singular, the translation should be “The lady’s son is nice”.  Both of them are correct translations and they can be tricky.  Be clear-minded when you analyze Latin sentences and don’t get trapped.

Next,

      Fēmina fīliō bona est.  =  The lady is nice to the son. 

      Fēmina fīliī bona est.  = The son’s lady is nice.

These two sentences should be relatively easy if you understand that fīliō is the dative singular of fīlius and fīliī is the genitive singular of fīlius, while interpreting fīliī as the plural of fīlius does not fit.

superat = he conquers, and fluvius = river, which belongs to the first subgroup.  Thus,

      Servus fluvium superat.  =  The slave conquers the river.

      Fluvius servum superat.  =  The river conquers the slave.

These two sentences are easy to understand if you can see that fluvium is the accusative of fluvius and servum is the accusative of servus. 

There are some transitive Latin verbs that require their object(s) to be only dative instead of accusative.  Three examples of them are pārēre = obey, imperāre = to give order to, and respondēre = respond to.

We need a new Latin word, regina = queen.  It will be great if you can see it as a first declension noun and it is feminine. 

      Fēmina est regīna. = That lady is the queen.

      Regina servīs imperat. =  The queen orders (gives order to) slaves.

      Servī reginae pāret. = the slaves obey (to) the queen.

      Fīlius amicō respondet. = the son responds to (his) friend. 

In the above four sentences, servīs is the dative plural of servus, meaning “to the slaves”, reginae is the dative singular of regina, meaning “to the queen”, while amicō is the dative singular of amicus, meaning “to the friend”.  With these interpretations, the translations should be easy to understand. 

Gladius = sword, is a masculine of the first subgroup noun, et = and, oppugant = they attack, and oppugat = he attacks.  These words are needed in the sentence below:

      Fīlius et amicī servōs oppugant.  = the son and (his) friends attack slaves. 

      Fīlius amicī servōs oppugat. = the friend’s son attacks slaves.

amicī is the nominative plural of amicus in the first sentence, and servōs is the accusative plural of servus, indicating it is used as a direct verb object.  However, amicī in the second sentence is the genitive singular of amicus.  Also, in the second sentence, both the subject fīlius and the verb oppugat imply that the subject is singular. 

Second Subgroup of Second Declension

As we said before, not all neuter nouns belong to the second declension group, but all neuter nouns with a nominative singular ending –um do belong to the second declension

group¹⁰.  frūmentum = grain, is the first example and let’s decline itnow.

      Table Seven:   Base Form:  frūment-

            Singular ending   Plural  ending

Nom.  frūmentum -um   frūmenta -a

Gen.  frūmentī -ī   frūmentōrūm -ōrūm

Dat.  frūmentō -ō   frūmentīs -īs

Acc.  frūmentum -um   frūmenta -a

Abl.  frūmentō -ō   frūmentīs -īs 

Believe or not, here comes the second one:  oppidum = town and decline it if you can.

      Table Eight:   Base Form:  oppid-

            Singular ending   Plural  ending

Nom.  oppidum -um   oppida  -a

Gen.  oppidī  -ī   oppiōrūm -ōrūm

Dat.  oppidō  -ō   oppidīs  -īs

Acc.  oppidum -um   oppida   -a

Abl.  oppidō  -ō   oppidīs  -īs 

How about the third one of this second subgroup?  proelium = battle.

      Table Nine:   Base Form:  proeli-

            Singular ending   Plural  ending

Nom.  proelium -um   proelia  -a

Gen.  proeliī   -ī   proeliōrūm -ōrūm

Dat.  proeliō  -ō   proeliīs  -īs

Acc.  proelium -um   proelia  -a

Abl.  proeliō  -ō   proeliīs  -īs

Applying the Second Subgroup Nouns of Second Declension

Analyzing Latin sentences with nouns of second kind of second declension give us another chance to test our memory and practice our understanding.  Can I assume such practice is fun rather than a torture?  Maybe not? 

Latin for English word have is habēre.  He has = habet.  So,

      Oppidum cōpiam frūmentī habet.  =  The town has a lot of grain (food).

Here, frūmentī is the genitive singular of frūmentum, representing a possessive or dependent relationship.

      Servī oppidium oppugant.  =  The slaves attack the town. 

Servī is the nominative plural here and oppidium is the accusative of oppidium¹¹.   

The English word camp is singular, however, its Latin counterpart, castra, is plural with a neuter gender, representing a singular concept in English.  Verbs used in association with castra must be plural, too.  mittere is the Latin verb for to send.  mittet = he sends and mittunt = they send.

      Agricolae castrīs frūmentum mittunt. = The farmers send grain to the camp.

In this sentence, agricolae is the nominative plural as the subject.  frūmentum is the accusative of frūmentum (they look the same as it is a neuter).  castrīs could be dative or ablative, but in this sentence it is dative plural, indicating the meaning of “to the camp”. 

Third Subgroup of Second Declension

So, we are not done with the second declension yet.  We said that all masculine nouns with a nominative singular ending –us belong to the second declension.  Actually there are some other masculine nouns also belong to the second declension.  What are they?  They are the masculine ones with a nominative singular ending being –er or –ir.  These masculine nouns form the third subgroup of the second declension group. 

Now, let’s learn how to decline a noun in this subgroup.  Actually except the nominative singular ending, all the other endings are the same as those of the first subgroup. However, a student has to pay a close attention to whether a noun in this subgroup has an –er ending or an –ir ending for its nominative singular. 

puer = boy is a noun of this third subgroup and we will decline this first:

      Table Ten:   Base Form:  puer-

            Singular ending   Plural  ending

Nom.  puer  -(to be learned) puerī  -ī

Gen.  puerī  -ī   puerōrūm -ōrūm

Dat.  puerō  -ō   puerīs  -īs

Acc.  puerum -um   puerōs  -ōs

Abl.  puerō  -ō   puerīs  -īs

Note that no ending is added to the base to form its nominative singular.  In other words, the base form and the nominative singular form are the same. 

Let’s try a noun in this subgroup with a nominative singular ending –ir:  vir = man.  So vir is the nominative singular case, but what is the base form of this noun?  Well, let’s try to get an answer in its declension list below:

      Table Eleven:   Base Form:  vir-

            Singular ending   Plural  ending

Nom.  vir  - (to be learned) virī  -ī

Gen.  virī  -ī   virōrūm -ōrūm

Dat.  virō  -ō   virīs  -īs

Acc.  virum  -um   virōs  -ōs

Abl.  virō  -ō   virīs  -īs

Again, the base form vir- and the nominative singular case vir look the same.  Is this a common feature of the nouns in this subgroup?  Good question, but “no” is the disappointing answer.   

Take another example in this subgroup:  ager = field and it is the nominative singular.  By simply looking at ager, we have no way to know its base form this time.  Looking up in a Latin dictionary, you will find its base form is even stranger.  It is agr- with the letter e in ager dropped¹².  With this base form we decline the word ager as follows.

      Table Twelve:   Base Form:  agr-

            Singular ending   Plural  ending

Nom.  ager  -(to be learned) agrī  -ī

Gen.  agrī  -ī   agrōrūm -ōrūm

Dat.  agrō  -ō   agrīs  -īs

Acc.  agrum  -um   agrōs  -ōs

Abl.  agrō  -ō   agrīs  -īs 

That does not look like anything easy to remember¹³.  By simply looking at the nominative singular case, we won’t be able to know the base form at all for this subgroup of nouns.  Sometimes the two things look the same, as in the cases of puer and vir, sometime they look different, as shown by the case of ager.  Actually the trick to know the base form of any Latin noun (no matter what declension group it is in) is to look at the genitive singular case and by dropping the ending of the genitive singular case, we’ll get the base form of a Latin noun.  virī is the genitive singular and so vir- must be the base form.  Knowing the base form, we can then proceed to decline a noun for the other grammatical cases.  That is why, when any Latin dictionary lists a noun, it lists not only the nominative case, but also the genitive case.  From now on, when you learn a Latin noun, you MUST pay attention to both of its nominative singular and genitive singular. 

We have many more words like ager in which the letter e is dropped from the base form.  I’ll list two more below for you to practice declension for each of them:

      Nominative singular  Base form  English Meaning

            liber         librī   book

            magister        magistrī   master 

Finally, we are done with the second declension group.  But this is only the second declension.  It goes up to fifth, remember?  So now what do you think of Latin grammarians:  Are they super intelligent or a bunch of crazy people to “invent” such killing grammatical rules?   

Now I won’t blame you if you are feeling or even cursing how hard Latin could be.  Up to this point, we have learned two declensions of Latin nouns with four sets of endings.   

Also, in order to save time and space, we’ll stop doing sentence analysis.  Hope you have had a good taste of analyzing sentences above and keep practicing them on your own. 
Third Declension

We have no other way around but keep going.  For the third subgroup of the second declension we just learned, at least we have one “judgment” to count on:  the ending of a noun’s nominative singular is either -er or -ir.  It’s just that we need to remember both nominative singular and genitive singular cases so that we’ll be able to detect which declension group a noun belongs and what its base form looks like. 

For nouns in the third declension, learning them is more demanding on our memory.  The nominative ending of a noun in this group can be anything.  The other thing certain about this group is that the genitive singular ends in -is.  This is the criterion you can use to judge whether a noun belongs to the third declension or not¹⁴.   

First Subgroup of Third Declension

Nouns in this third declension are further divided into two subgroups.  Both masculine and feminine nouns of third declension (i.e., with a genitive singular ending “-is”) belong to the first subgroup, while all the neuter nouns of third declension belong to the second subgroup.   

For instance, consul is the masculine Latin word for English consul and its Latin genitive singular is consulis.  With that, we decline this noun.

Table Thirteen:   Base Form:  consol-

            Singular ending   Plural  ending

Nom.  consul  (to be learned) consulēs -ēs

Gen.  consulis -is   consulum -um

Dat.  consulī  -ī   consulibus -ibus

Acc.  consulem  -em   consulēs  -ēs

Abl.  consule -e   consulibus  -ibus

This is another entirely different set of endings for you to remember.  Hope we all somehow have a deft mnemonic anchorage to meet the challenge and help us hook all these deep in our brains. 

When you see consul and its genitive singular consulis, do not take it for granted that we can add the ending -is to the nominative singular of a noun in this subgroup to form its genitive singular.  The next example will outsmart such “guess”.   

custōs = guard is a masculine nominative singular, but its genitive singular is custōdis (NOT custōsis).  Only with this correct genitive singular and its associated base form “custōd-” can we do its declension list correctly as below.

Table Fourteen:   Base Form:  custōd-

            Singular ending   Plural  ending

Nom.  custōs  (to be learned) custōdēs -ēs

Gen.  custōdis -is   custōdum -um

Dat.  custōdī  -ī   custōdibus -ibus

Acc.  custōdem  -em   custōdēs  -ēs

Abl.  custōde -e   custōdibus  -ibus

Now you see that the genitive singular is “custōdis”, not “custōsis”. 

We have seen that for some nouns in the third subgroup of the second declension, the letter e is dropped in the base form.  Now, for some nouns in this first subgroup of third declension, a consonant may even get changed in the base form.  Here is an example:

dux, = leader, is a masculine nominative singular, but its genitive singular is ducis, rather than duxis.  Below is its full declension list:

      Table Fifteen:   Base Form:  duc-

            Singular ending   Plural  ending

Nom.  dux  (to be learned) ducēs  -ēs

Gen.  ducis  -is   ducum  -um

Dat.  ducī  -ī   ducibus -ibus

Acc.  ducem   -em   ducēs   -ēs

Abl.  duce  -e   ducibus  -ibus

In this example, the consonant x change into c. 

Yet, the consonant x does not always change into c.  Take a look at rex.

rex = king is the masculine nominative singular and its genitive singular is regis, not rexis, nor recis. Its declension list is therefore:

      Table Sixteen:   Base Form:  reg-

            Singular ending   Plural  ending

Nom.  rex  (to be learned) regēs  -ēs

Gen.  regis  -is   regum  -um

Dat.  regī  -ī   regibus  -ibus

Acc.  regem   -em   regēs   -ēs

Abl.  rege  -e   regibus  -ibus 

Again, below is a list of nouns in this first subgroup of third declension in their nominative singular and genitive singular forms, provided for you to practice.

      Nominative singular  Genitive singular English meaning

            legiō (feminine)  legiōnis  legion

            mīles (male)   militis   soldier

            mūnitiō (f)   mūnitiōnis  fortification

            uxor (f)   uxoris   wife

            Iūnō (f)   Iūnōnis   a person’s name 

Second Subgroup of Third Declension

What does this group consist of?  The answer is “all the neuter nouns” whose genitive singular ending is -is.  Actually the endings of this second subgroup are the same as those of the first subgroup except for two occasions:  nominative (both singular and plural) and accusative (both singular and plural).  Then why do we need this subgroup?  Can’t we lump them into the first subgroup and make it an entire group including all nouns in the third declension group?  Well, remember we talked previously about one feature of neuter nouns:  that is, singular or plural, nouns of this gender have the same nominative and accusative cases.  For this only reason, neuter nouns of third declension are singled out as a separate subgroup¹⁵.  The plural ending for nominative and accusative for this subgroup is “-a”, while the singular ending for nominative and accusative needs to be learned. 

      The first declension list of this subgroup is caput.  caput = head/capital is the nominative singular and its genitive is capitis.  Now decline it in the following:

      Table Seventeen:   Base Form:  capit-

            Singular ending   Plural  ending

Nom.  caput   (to be learned) capita  -a

Gen.  capitis   -is   capitum -um

Dat.  capitī  -ī   capitibus -ibus

Acc.  caput   (to be learned)  capita   -a

Abl.  capite  -e   capitibus  -ibus

As we can see now, the nominative caput and the accusative caput are the same (singular), while the nominative capita and the accusative capita are the same (plural). 

The second example of this subgroup is corpus¹⁶ = body.  corpus is a neuter nominative singular and its genitive singular is corporis.  Now its declension list is:

            Table Eighteen:  Base Form:  corpor-

            Singular ending   Plural  ending

Nom.  corpus   (to be learned) corpora -a

Gen.  corporis -is   corporum -um

Dat.  corporī  -ī   corporibus -ibus

Acc.  corpus   (to be learned)  corpora  -a

Abl.  corpore  -e   corporibus  -ibus 

One more confusing one:  iter = road/route is a neuter nominative singular and its genitive singular is itineris.  Although iter ends in -er, it does not belong to the third subgroup of the second declension, which includes only masculine nouns whose nominative singular ending in -er or -ir, for iter is a neuter, not masculine. 

      Table Nineteen:  Base Form:  itiner-

            Singular ending   Plural  ending

Nom.  iter   (to be learned) itinera   -a

Gen.  itineris  -is   itinerum -um

Dat.  itinerī  -ī   itineribus -ibus

Acc.  iter   (to be learned)  itinera   -a

Abl.  itinere  -e   itineribus  -ibus 

Once again, a list of nouns in this subgroup is provided below if you have a gullible desire to practice more of their declensions.

      Masculine singular  Genitive singular  English Meaning

            flūmen (neuter)  flūminis    river

            genus (neuter)   generis    race/kind

            nomen (neuter)  nominis   name

            vulnus (neuter)  vulneris    wound 

A useful observation:  in this subgroup of neuter nouns, when nominative singular of a noun ends in “-men”, its genitive singular ends in “-minis”.  When a nominative singular ends in “-us”, its genitive singular ends in either “-oris” or “-eris”. 

Believe or not, we are at the finishing line of the third declension.  Now are you encouraged to do more?  There are total five declensions and we’ve learned three of them.  Three done and two more to go; are you in a moot to go further?  Actually, I am not.  Let’s take a break.  Let’s give ourselves an excuse by saying that we are right now at a jamming point of Latin nouns.  So, we’d better look back and summarize what has been learned.  We’ll assume that this is a rewarding process, pet our own shoulders and say that, to learn three declensions in one such lecture is already a great achievement envied by many.  We’ll reflux our muscles and deal the other two declensions later.  Don’t forget:  less is more. 

Summary of the First Three Declensions

The endings of the first declension group is relative simple and straightforward:

                  First Declension Endings

                  Singular  Plural

      Nom.  -a   - ae

      Gen.  -ae   -ārum

      Dat.  -ae   -īs

      Acc.  -am   -ās

      Abl.  -ā   -īs

Each noun in this group have its nominative singular end in “-a”.  Most of the nouns in this group are feminine in gender.  The four exceptions to remember are agricola = farmer, incola = inhabitant, nauta = sailor, and poeta = poet. 

The second declension group has three subgroups.  The first subgroup has its endings as follows:

      Endings of First Subgroup, Second Declension:

                  Singular  Plural

      Nom.  -us   -ī

      Gen.  -ī   -ōrum

      Dat.  -ō   -īs

      Acc.  -um   -ōs

      Abl.  -ō   -īs

This subgroup contains masculine nouns whose nominative singular ends in “-us”. 

      Endings of Second Subgroup, Second Declension:

                  Singular  Plural

      Nom.  -um   -a

      Gen.  -ī   -ōrum

      Dat.  -ō   -īs

      Acc.  -um   -a

      Abl.  -ō   -īs

This subgroup contains neuter nouns whose nominative singular ends in “-um”.  The other point worth noticing is that for neuter nouns, the endings of nominative and accusative, singular or plural, are the same. 

      Endings of Third Subgroup, Second Declension:

                  Singular  Plural

      Nom.  -er or -ir¹⁷  -ī

      Gen.  -ī   -ōrum

      Dat.  -ō   -īs

      Acc.  -um   -ōs

      Abl.  -ō   -īs

This subgroup contains all masculine nouns with their nominative singular ending in either –er or –ir.   

Why are these three subgroup grouped into the same second declension group?  The reason is that any noun from any one of these three subgroup will have its genitive singular end in “-ī”.  This distinguishes a noun of the second declension from any other noun from any other declensions. 

The third declension has two subgroups, too.

      Endings of First Subgroup, Third Declension:

                  Singular  Plural

      Nom.  (to be learned)  -ēs

      Gen.  -is   -um

      Dat.  -ī   -ibus

      Acc.  -em     -ēs

      Abl.  -e   -ibus

This first subgroup contains nouns, either masculine or feminine whose nominative singular ending could be anything, but whose genitive singular ending must be “-is”. 

      Endings of Second Subgroup, Third Declension:

                  Singular  Plural

      Nom.  (to be learned)  -a

      Gen.  -is   -um

      Dat.  -ī   -ibus

      Acc.  (same as Nom.) -a

      Abl.  -e   -ibus

This second subgroup contains only neuter nouns whose nominative singular ending could be anything, but whose genitive singular ending must be “-is”.  Again, since this is for neuter nouns, the nominative endings and the accusative endings, singular or plural, look exactly the same.   

Lastly, what’s unique about each declension group is its genitive singular ending.  For instance, the genitive singular of the first declension group is “-ae”, that of the second declension is “ī”, and that of the third declension is “is”.  Remembering this is important, as the genitive singular ending helps us find what the base form is and facilitates the process of declension. 

I know that Latin is overwhelming, but I hope at the end of this “lecture” you feel that your intelligence meets the challenge and you are encouraged to do more.  I do not the slightest intent to intimidate anyone but want to tell you that the conjugation system of Latin verbs could be much “worse” than declension system of Latin nouns.  The bright side is that learning Latin IS rewarding.  If you have a great command of both Latin conjugation and declension, you will find French, Spanish, Italian, German, and even English a lot easier.  In fact, if you have learned Latin well enough, you will feel as you have learned all of these major western languages.  In one sense, Latin is the mother of all these “European local tongues”.