They were to have left at 7 last night. 他们本来计划昨晚7点离开的。 5.would(should)+动词原形 把助动词be变为过去式,把will,shall变为过去式。 例如: I told them that I would not go with them,if it rained. 我告诉他们,如果下雨我就不和他们一起去了。 He di...