这周语法课，动词时态笔记。

Verb tense refers to when an action happened. 时间。

• Past - has happened in the past
  • 例：I lived in China.
• Present - is happening now
  • 例：I live in St. Louis.
• Future - will happen in the future
  • 例：I will live in Las Vegas when I retire.

Tense also determines if an action continues for a time. 状态

• Perfect: action is completely done or finished. 完成状态 In other words, whatever the action is or was, it is completed when the perfect tense is used.
• Progressive: action is happening now and will continue into the future. 连续状态 
• Perfect progressive: action was completed, but it continued over a period of time or has some effect on the present or future. 完成连续状态

时间和状态组合成时态tenses。