下列名词后的表语从句或同位语从句，也用"should + 动词原形" 表示虚拟语气：
* demand (要求), desire (请求),requirment (要求)
* advice (劝告), recommendation (建议),suggestion (建议)
* order (命令)
* necessity (必要地), preference (优先)
* proposal (计划), plan (计划), idea (办法)
1.The advice is that we (should 可省略，下同) leave at once.
(名词advice，should + leave) (表示加以劝告)
2. My idea is that we (should) get more people to attend the conference.
(idea, should + get) (表示做出主意)
3. I make a proposal that we (should) hold a meeting next week.
(proposal, should + hold) (表示做出计划)
句型：It is (或was) + 形容词(或过去分词) + that …… +should + 动词原形……
句子：It is natural that she should do so. (形容词natural, should+动词原形do)
* natural (自然的), appropriate (适当的),advisable (合适的), preferable (更可取的), better (更好的)
* necessary (必须的), important (重要的), imperative (急需的), urgent (急迫的), essential (本质的), vital (必不可少的)
* probable (很可能的), possible (可能的)
* desirable (极好的)
* required (需要的), demanded (要求), requested (被请求的), desired (要求)
* suggested (建议), recommended (推荐)
* orderd (命令)
1. It is necessary that we (should 可省略,下同）have a walk now.
(necessary, should + have) (表示有需要去散步)
2.It was necessary that we (should) make everything ready ahead of time.
(necessary, should + make) (表示有必要事先做好准备)
3. It is required that nobody (should) smoke here.
(required, should + smoke) (表示要求不要在此抽烟)
4. It is important that every pupil (should) be able to understand the rule of school.
(important, should + be) (表示重要的是学生都能了解校规)
5. It's important that we (should) take good care of the patient.
(important, should + take) (表示重要的是照顾好病人)
1. If time permits, we'll go fishing together.
1. If it had rained yesterday, we would have stayed at home.
* 这种句子一般由"从句"（Subordinate Clause)和"主句"(Main Clause)组成。如上
If it had rained yesterday, we would have stayed at home.
"If it had rained yesterday" 就是"从句"；"we would have stayed at home" 则为"主句。
从句：if + 主语 + 动词的过去式(be 用 were) + ……
主句：主语 + would (should, could , might) + 动词原形 + ……
1.If I were you, I would go with him.
(从句 If I were you, 主句 I would go with him.)
2.If I were you, I should buy it.
3.If I had time, I would study French. (如果有时间，我会学习法文。）
4. If she knew English, she would not ask me for help. (如果她懂英文，她就不必要我帮了。)
注意：如果动作在进行中，主句要用："主语 + would be + 进行式动词 + ……"
5. If they were here, he would be speaking to them now.
(从句用过去式动词were, 主句用 would be speaking)