Modals

Modal perfects for past speculation and regret

简介

情态动词完成式（情态动词 + have + 过去分词）是用来推测过去的高级结构。"must have""might have""can't have""should have""could have"——每一种都表达不同程度的确定性或不同类型的判断。

这些结构对讨论过去的可能性、表达遗憾、分析"本来可能会怎样"至关重要。在英语的日常对话和写作中随处可见。

中文里"一定做过""可能做过""本来应该做"表达类似的意思，但英语用一套非常系统的结构来区分这些细微差别。掌握情态完成式，你就能精确地表达对过去事件的各种复杂想法。

主题

本章全部英语语法（10）

• Modal Perfects Modal + have + past participle for past speculation or regret
• Modal Perfect Continuous Modal + have been + -ing for duration before past speculation
• would rather / would sooner Expressing preferences, often contrary to expectations
• be + to infinitive Formal structures for plans, destiny, and instructions
• needn't have done vs didn't need to Unnecessary past actions - done vs not done
• can't have vs mustn't have Deductions about impossible past events
• would have + past participle Hypothetical past actions or missed opportunities
• could have + past participle Past possibilities that did not happen
• might have / could have (Criticism) Criticizing someone for not doing something
• would (Annoying Habits) Expressing irritation about typical behavior