英语情态动词课程 - TOEIC®备考

在英语中,情态动词(或称情态助动词)是一类特殊的动词,用来表达可能性、义务、能力、许可、建议等多种语气和语义细微差别。
它们不遵循通常的动词变化规则:
- 第三人称单数时没有 -s(例如 he can, she must, it will),
- 否定和疑问句中不使用助动词 do(如 I cannot go / Can I go?),
- 直接跟动词原形,不加 "to"(如 I can swim,而不是 I can to swim)。
通常我们将情态动词分为三大类:
- 纯情态动词(core modals):
- 包括 can, could, may, might, must, shall, should, will, would(有时还包括在特定用法下的 dare 和 need)。
- 这些动词是缺陷动词:并非所有时态都存在(例如没有 canned 这种形式),且遵循上述特殊规则(无 -s,否定不用 do 等)。
- 半情态动词(quasi-modals):
- 它们表达类似的意义(义务、能力、将来等),但部分表现为普通动词。
- 例如 have to, be able to, need(作为普通动词), dare(作为普通动词), ought to, used to, be going to 等。
- 部分半情态动词可以带 -s(He has to go),可以用过去时(I had to go),或可以使用助动词 do(Do you need to go?)。
- 情态短语(periphrastic modals):
- 这些是由短语(通常用 be 或 have 构成)承担情态功能(如 be allowed to, be about to, would rather 等)。
- 它们不像纯情态动词那样“缺陷”,可以按照普通动词规则变化(如 He is allowed to go, They were about to leave 等)。
下面是情态动词功能的总结表。每个功能我们都写了专门课程,欢迎查阅。
功能 | 纯情态动词 | 半情态动词 | 情态短语 |
---|---|---|---|
能力 (= 能做某事) | can / can't could / couldn’t | be able to | manage to succeed in know how to be capable of |
许可 (= 有权/被允许) | can / could / may / might | be allowed to have the right to have permission to | |
义务 (= 强制性义务,必要性) | must / shall | have (got) to ought to | be required to be to + 动词原形 |
禁止 (= 没有权利/被禁止) | can’t / cannot mustn’t may not | not allowed to | |
无义务 (= 没必要) | don’t have to don’t need to needn’t | be not required to | |
建议 (= 推荐/强烈建议) | should / shouldn’t | ought to ought not to had better | you are advised to... |
建议/提议 (= 提出某种建议或方案) | could / shall | why don’t we...? | |
意图/将来 (= 将来、计划、意图、打算) | will / shall | be going to | be about to |
可能性/不确定性 (= 确定/可能的程度) | may / must / can’t | be likely to be bound to | be supposed to be like |
偏好/愿望 (= 想要某物、表达偏好) | would | would like would rather would sooner |