二、虛擬語氣
非真实条件句的虚拟语气
就是說，非真实条件句表示条件从句假设的动作客观上未发生，只是主观虚拟在这个动作发生的情况下主句动作的反馈。。 。
此時be的各種人稱都要用 were。
If I had enough money, I would buy myself a computer first of all. （如果我有足够的钱，我首先要自己买一台电脑 。）
对 现在的 虚拟
表示与现在事实相反的情况。從句改為過去式，主句改為would/should/could/might + 動詞原形吖。
对 过去的 虚拟
表示与过去事实相反的情况。從句改為過去完成式，主句would/should/could/might + have done
对 将来的 虛拟
從句改為過去式、were to + 動詞原形、should + 動詞原形，主句為would/should/could/might + 動詞原形
非真实条件句省略if的情况
句中有should、had、were时 ，可以省略if，而把should、had、were提至主语前，从句形成部分倒装结构。
Had I worked hard，I would surely succeed.（如果我当时努力学习的话，我一定会成功的。）
Were she my daughter, Iwouldn’tallow her to study abroad.（如果她是我的女儿，我就不让她出国学习了。）
兩個固定搭配
Were it not for…“ 要不是… ”;（=“if it were not for…“）
Were it not for your help,I would never be a good manager.
Had it not been for…“当时要不是… ”（=“If it hadn’t been for…”）
Had it not been for you,I would have lost my way.
混合虚拟语气
有时非真实条件句谓语动词表示的动作与主句谓语动词表示的动作发生的时间不一致 ，此时主句与从句谓语动词的形式根据各自发生的时间来确定。
| 句子的部分 | 动作发生的时间 | 谓语动词形式 |
|---|---|---|
| 条件句 (If-clause) / 从句 | 过去 (与过去事实相反) | had done (过去完成时) |
| 现在 (与现在事实相反) | 过去式 (通常用 were) | |
| 将来 (与将来事实相反) | 过去式, were to do, should do | |
| 结果句 (Main Clause) / 主句 | 过去 (与过去事实相反) | would/should/could/might have done |
| 现在 (与现在事实相反) | would/should/could/might do | |
| 将来 (与将来事实相反) | would/should/could/might do |
- If I had studied harder at school, I would have a better job now.（如果我以前學得更勤力，我而家就有份好啲嘅工。）
含蓄虚拟语气
在虚拟语气中，条件并不总是以“If”引导的条件从句形式出现，它经常会隐含在句子中的其他结构中。这种现象被称为“虚拟条件的隐含”（Implied Conditions）。
1. 介词短语 (Prepositional Phrases)
这些短语常用来代替一个与过去事实相反的条件从句（虚拟语气过去完成时）。
| 结构 | 含义 | 示例 | 对应的条件从句 |
|---|---|---|---|
| But for… | 要不是；若非… | But for the delay, we would have arrived on time. | If there hadn’t been a delay… |
| Without… | 要是没有… | Without your help, I couldn’t have finished the task. | If you hadn’t helped me… |
| With… | 要是有… | With a little more effort, he might have succeeded. | If he had made a little more effort… |
| In your place / In his shoes | 设身处地；如果我是你/他 | In your place, I would apologize. | If I were you… |
2. 副词 (Adverbs)
最常用的是 otherwise，它用来表示“否则”（即与前面提到的事实相反的条件）。
| 结构 | 含义 | 示例 | 对应的条件从句 |
|---|---|---|---|
| Otherwise | 否则；不然的话 | He ran fast; otherwise, he would have missed the train. | If he hadn’t run fast… |
3. 连词 (Conjunctions)
or / or else：常用于连接两个并列句，表示“如果不做前面的事，就会出现后面的结果”。
Stop talking, or I will ask you to leave.
(隐含条件：If you don’t stop talking…)
but that：常用于 It is/was not/never that… 结构，表示“要不是…”。
It never rains but that the sun shines afterward.
(隐含条件：There is no rain that is not followed by sunshine.) (虽然这个例子中主句不是严格的虚拟语气，但它显示了 but that 隐含条件的作用。)
4. 上下文或句子中的其他名词/短语
有时，一个名词或一个形容词短语本身就隐含了一个条件。
| 结构 | 示例 | 隐含条件 |
|---|---|---|
| 名词 | A careful person would not make such a mistake. | If a person were careful… |
| 动词不定式 | To hear him talk, you would think he was the boss. | If you heard him talk… |
| 分词短语 | Having been ill, she would have missed the exam. | If she had been ill… |
其他从句中的虚拟语气
主语从句中的虚拟语气
以下句型中，主语从句常用虚拟语气，谓语动词用“(sh ould+)动词原形”。
**1. 表示“重要性、必要性、评价”的形容词
这些句型通常以 It is/was + 形容词 + that… 结构出现。8
| 句型结构 (主句) | 常用形容词 (Adjectives) | that 从句谓语动词 | 例子 (您的提供) |
|---|---|---|---|
| It is/was… that… | important (重要的) | (should) + 动词原形 | It is very important that one (should) master the skills of computer. |
| necessary (必要的) | It is necessary that he (should) complete the report today. (他今天完成这份报告是必要的。) | ||
| essential (本质的/极其重要的) | It is essential that she (should) be present at the meeting. (她出席会议是极其重要的。) | ||
| vital (极重要的) | |||
| imperative (迫切的/紧急的) | |||
| natural (自然的) | It is natural that they (should) feel tired after the long journey. (长途旅行后他们感到疲惫是很自然的。) | ||
| strange (奇怪的) | It is strange that he (should) refuse our generous offer. (他拒绝我们慷慨的提议是很奇怪的。) | ||
| surprising (令人惊讶的) | |||
| unthinkable (不可思议的) | |||
| 注：对于 impossible 和 unthinkable 等词，有时也会用陈述语气，但在表达意想不到的情况时，虚拟语气更常见。 |
2. 表示“规则、情感、判断”的名词
这些句型通常以 It is/was + 名词 (a/an…) + that… 结构出现。5
| 句型结构 (主句) | 常用名词 (Nouns) | that 从句谓语动词 | 例子 (您的提供) |
|---|---|---|---|
| It is/was a… that… | rule (规则/规定) | (should) + 动词原形 | It is a rule that everyone (should) obey the laws. |
| shame (遗憾/可惜) | It is a shame that they (should) miss the opportunity. (他们错过这个机会真可惜。) | ||
| honour (荣幸/光荣) | It is an honour that you (should) be invited to speak. (您被邀请发言是荣幸。) | ||
| surprise (惊讶) | It was a surprise that he (should) resign without notice. (他未通知就辞职令人惊讶。) | ||
| wonder (奇怪) | It is no wonder that the plan (should) fail without proper funding. (没有适当的资金计划失败不足为奇。) |
**3. 表示“建议、命令、要求”的动词 (的过去分词形式)**7
这些句型通常以 It is/was + 过去分词 (V-ed) + that… 结构出现。
| 句型结构 (主句) | 常用过去分词 (V-ed) | that 从句谓语动词 | 例子 (您的提供) |
|---|---|---|---|
| It is/was… that… | advised (建议) | (should) + 动词原形 | It is advised that one (should) take plenty of boiled water. |
| suggested (建议) | It is suggested that the meeting (should) be postponed. (建议会议延期。) | ||
| requested (要求) | It is requested that all files (should) be backed up immediately. (要求所有文件立即备份。) | ||
| required (要求) | It is required that every employee (should) wear a uniform. (规定每位员工都应穿制服。) | ||
| ordered (命令) | It was ordered that no one (should) leave the base. (命令任何人都不得离开基地。) | ||
| proposed (提议) | It is proposed that a new committee (should) be established. (提议成立一个新的委员会。) | ||
| decided (决定) | It was decided that the project (should) go ahead next month. (已决定项目下个月继续进行。) |
💡 核心总结 (The Subjunctive Rule)
- 结构： 主语从句 (通常是 It) + 系动词 + 表达要求、建议、必要性等含义的表语 + that 从句。
- 虚拟： that 从句的谓语动词固定为： (should) + 动词原形。
宾语从句中的虚拟语气
1. 在 wish 后的宾语从句中
wish 后面的从句用来表示与事实相反或不可能实现的愿望，其时态必须向过去推移一步（即“降档”）。
- I wish + 過去式 → 表示「對現在事實相反嘅願望」
- I wish + 過去完成式 → 表示「對過去事實相反嘅願望」
| 愿望对象 | 对应事实 | 宾语从句谓语动词 | 例子 (您的提供) |
|---|---|---|---|
| 与现在事实相反的愿望 | 现在的实际情况 | 一般过去时 (be 动词一律用 were) | I wish I were ten years younger. (但愿我能年轻十岁。) |
| 与将来事实相反的愿望 | 将来的可能性 | would / could + 动词原形 | I wish I could fly to the moon someday. (我希望有一天能飞到月球上。) |
| 与过去事实相反的愿望 | 过去的实际情况 | 过去完成时 (had + V-ed) | I wish you had come to the lecture. (你当时来听报告就好了。) |
2. 在 would rather 后的宾语从句中
would rather (或 would sooner) 后接 that 从句，表示“宁愿（某人/某事）现在/过去做某事”，同样采用降档时态。
| 宁愿的对象 | 对应事实 | 宾语从句谓语动词 | 例子 (您的提供) |
|---|---|---|---|
| 与现在或将来事实相反 | 现在的或将来的情况 | 一般过去时 | I’d rather you came tomorrow than today. (我宁愿你明天来，而不是今天。) |
| I’d rather we had a rest now. (我希望我们现在休息一下。) | |||
| 与过去事实相反 | 过去的实际情况 | 过去完成时 (had + V-ed) | I’d rather you hadn’t told me about it. (我宁愿你没有告诉我。) |
3. 在表示“坚持、建议、命令、要求”的动词后的宾语从句中 10
这些动词的主旨是提出一种要求或提议，而不是描述事实，因此其后的宾语从句也用虚拟语气。
| 动词类型 (Verbs) | 常用动词 | 宾语从句谓语动词 | 例子 (您的提供) |
|---|---|---|---|
| 命令 (Command) | order, command, dictate | (should) + 动词原形 | The commander ordered that the bridge (should) be blown up. |
| 建议 (Suggestion) | suggest, propose, advise | My father suggests that I (should) take enough sleep before the final examination. | |
| 要求 (Requirement) | demand, require, request | ||
| 坚持 (Insistence) | insist | He insisted that I (should) come to his office at one o’clock. | |
例外注意： 当 suggest 和 insist 表示“陈述事实或看法”时，宾语从句使用陈述语气。例如：He insisted that he was innocent. (他坚持说他是无辜的。) |
综合总结
这三组句型体现了虚拟语气在不同情境下的应用原则：
- Wish / Would rather： 使用时态的“降档”来表示与现在、将来或过去事实的相反或不可能。
- Suggest / Order / Insist (等)： 使用 (should) + 动词原形 来表示一种尚未实现的、带有命令或提议性质的动作。
表语从句中的虚拟语气
一、表示“要求、建议、命令”的名词后的从句
当主句的主语是表示“要求、建议、命令”的名词时，其后的表语从句或同位语从句中，谓语动词也要使用虚拟语气，即 (should) + 动词原形。
| 句型结构 (主句) | 常用名词 (Nouns) | 从句谓语动词 | 例子 (您的提供) |
|---|---|---|---|
| My/The… is that… | advice (建议) | (should) + 动词原形 | My advice is that you (should) quit smoking. |
| My/The… is that… | suggestion (建议) | (should) + 动词原形 | My suggestion is that we (should) get started as soon as possible. |
| 常见的这类名词有: | demand (要求) | The demand was that he (should) apologize publicly. | |
| order (命令) | His order was that they (should) proceed immediately. | ||
| insistence (坚持) | The insistence was that the report (should) be accurate. | ||
| requirement (要求) | |||
| request (请求) | |||
| proposal (建议) | |||
| command (命令) | |||
| decision (决定) |
二、AS IF / AS THOUGH 引导的从句 (貌似、仿佛)
当 as if 或 as though 引导的从句表示与事实相反的情况或假设时，该从句也使用虚拟语气，其规则与 wish 后的从句相似，即“降档”规则。
| 表达含义 | 对应事实 | 从句谓语动词 | 例子 (您的提供) |
|---|---|---|---|
| 与现在事实相反 | 现在的实际情况 | 一般过去时 (be 动词一律用 were) | It seems as though it were spring already. (看起来好像已经是春天了一样。—— 事实不是春天。) |
| It seemed as if the world were coming to an end! (仿佛世界末日即将来临！—— 事实不是世界末日。) | |||
| 与过去事实相反 | 过去的实际情况 | 过去完成时 (had + V-ed) | It looked as if she had seen a ghost. (看上去她好像见了鬼似的。—— 事实上没见过。) |
定语从句中的虚拟语气
定语从句中的虚拟语气：It is (high) time that...
这个句型意为：“是时候做某事了/早该做某事了”，用来表示应该做但实际还没做的事情，因此要使用虚拟语气。
在这个结构中，that 引导的从句是一个定语从句，修饰 time。
| 表达含义 | 句型结构 (主句) | that 从句谓语动词 | 例子 (您的提供) |
|---|---|---|---|
| 是时候做某事了 | It is time that… | 1. 一般过去时 | It’s high time we went to school. (我们早该去上学了。) |
| It is high time that… | 2. should + 动词原形 (should 不可省略) | It’s time that I should go to pick up my daughter at school. (我该去学校接我女儿了。) | |
| It’s time that the children should go to bed. (到了孩子们该睡觉的时间了。) |
核心要点和注意事项：
- 两种形式：
- 最常用且最地道 的虚拟形式是使用一般过去时（如：we went to school）。
- 使用 should + 动词原形 的形式也是正确的，但在这种结构中，should 不可以省略。
- 非虚拟形式：
- 当主语是
It时，这个句型还有一种非虚拟形式：It is time **to do** sth.(如：It’s time to go to school.)。 - 另一种是非虚拟形式的
for结构：It is time **for sb. to do** sth.(如：It’s time for the children to go to bed.)。
- 当主语是
💡 总结对比：
| 句型 | 含义 | 语法点 |
|---|---|---|
| It’s time that + S. + 过去式 | 虚拟语气：早该/是时候做某事了 | 强调未能及时，催促意味强。 |
| It’s time that + S. + should + V. | 虚拟语气：是时候做某事了 | should 不可省略。 |
| It’s time + to do sth. | 非虚拟语气：该做某事了 | 最简单、最直接的表达方式。 |
状语从句中的虚拟语气
一、方式状语从句中的虚拟语气 (As if / As though)
as if 或 as though 引导的从句，在表示与事实相反的比较和假设时，使用虚拟语气（即“时态降档”）。
| 表达含义 | 对应事实 | 从句谓语动词 | 例子 (您的提供) |
|---|---|---|---|
| 与现在事实相反 | 现在的实际情况 | 一般过去时 (be 动词一律用 were) | The young man with long hair walks as if he were a girl. (走起路来就像个小姑娘。— 事实不是小姑娘。) |
| 与过去事实相反 | 过去的实际情况 | 过去完成时 (had + V-ed) | The injured man acted as if nothing had happened. (行动起来仿佛什么事也没有一样。— 事实是受伤了。) |
| …as if they had just happened. (仿佛刚刚发生的一样。— 事实是已经过去了。) |
二、目的状语从句中的虚拟语气
目的状语从句表示主句动作的目的。当目的从句中需要强调可能性、必要性或预防性时，常使用情态动词来构成虚拟语气。5
| 引导词/短语 | 含义 | 从句谓语动词 | 例子 (您的提供) |
|---|---|---|---|
| in order that / so that | 以便，为了（常用于正式语体） | should / may / might / can / could / would + V 原形 | I hired a boat so that I could go fishing. (我租了一条船，这样我就可以去钓鱼了。) |
| for fear that | 唯恐，生怕 | should + V 原形 | He studied hard for fear that he should fail the exam. (他努力学习，生怕考试不及格。) |
| in case | 以防万一 | should + V 原形 或 陈述语气 | Bring some money in case you should use it. (带些钱以防能用到。) |
| lest | 唯恐，以免 | should + V 原形 | We spoke quietly lest we should wake the baby. (我们说话很轻，以免吵醒婴儿。) |
核心要点：
- 情态动词选择：在
so that/in order that引导的从句中，选择can/could/may/might来表示目的的可能性，选择should/will/would来表示意愿或倾向。 in case的特殊性：in case后面可以使用 should + 动词原形 来表示虚拟语气，但更常见和简洁的用法是陈述语气（如：*Bring some money in case you need it.*）
好的！这是一个非常实用的总结，指出了虚拟语气在口语和非正式写作中简化表达的现象。
您提供的例子集中在省略了主句，只保留了条件从句（If 引导）来表达假设或愿望。
下面是针对这些只保留从句的虚拟语气的整理和总结：
只保留从句的虚拟语气 (省略主句)
在口语或特定的表达中，为了简洁有力，虚拟语气的主句（通常是表示“结果”的部分）会被省略，只留下表达条件或愿望的从句。
一、What if...? 句型
| 句型 | 含义 | 从句谓语动词 | 完整句子的虚拟情景 | 例子 (您的提供) |
|---|---|---|---|---|
| What if…? | 要是…，怎么办？ (常表示对未来可能发生的担忧) | should + 动词原形 | 原句通常是：What should I do if I should fail? | What if I should fail? (万一失败，我该怎么办呢？) |
| 扩展用法 | 一般过去时 | What if we missed the train? (要是我们错过了火车怎么办？— 假设现在/将来) | ||
| 过去完成时 | What if they hadn’t told us the truth? (要是他们当时没有告诉我们真相怎么办？— 假设过去) |
二、If only...! 句型
| 句型 | 含义 | 表达愿望的时态 | 完整句子的虚拟情景 | 例子 (您的提供) |
|---|---|---|---|---|
| If only…! | 要是… 就好了/但愿… (语气比 I wish 更强烈) |
一般过去时 (与现在事实相反) | (It would be better) if only I were 20 years younger. | If only I were 20 years younger. (我要是再年轻 20 岁该多好啊！) |
| 扩展用法 | 但愿将来能 | would / could + V 原形 | If only you would listen to my advice! (但愿你肯听我的劝告！) | |
| 对过去表示遗憾 | 过去完成时 (had + V-ed) | If only I had studied harder for the exam! (我当初要是为考试更努力学习就好了！) |
💡 核心总结：
这两种省略主句的表达，本质上仍遵循条件句和愿望句的虚拟语气规则：
- 对未来的假设/担忧：**(should) + V 原形**
- 对现在的假设/愿望：一般过去时 (were)
- 对过去的假设/遗憾：过去完成时 (had done)