Review of Tenses Review of Tenses 时态是一种语法范畴，是用以表示各种 时间和动作方面的动词形式。 时间有四个主要方面：现在、过去、将 来、过去将来。 动作也有四种：一般、完成、进行、完 成进行。 时间和动作相结合，形成了16种时态。一般 完成 进 行 完成进 行 现 在 过 去 将来 过 去将 来 动作 时间 do/does did shall/ will do should/ would do have done had done shall/ will have done should/ would have done be doing was /were doing shall/ will be doing should/ would be doing have been doing had been doing shall/ will have been doing should/ would have been doing1. The Present Tense ( 一般现在时态) 1. 表示经常性，习惯性或重复发生的动作，常于频度副词连用
