would rather that somebody did宁愿；更愿意(表示现在或将来的愿望)
would rather that somebody had done宁愿；更愿意（表示过去的愿望）
Id rather you posted the letter right now. 我想让你现在去寄信。
Id rather you were not a celebrated actor. In that case, we could spend more time together.
Id rather that I hadnt seen her yesterday. 我情愿昨天没有看到她。
as if/though+主语+did/had done好像（表示现在或将来的情况用过去时；表示过去的情况用过去完成时）[参考句型4]
Our head teacher treats us as if we were her own children, so all the students in our class think highly of her.
Alan talked about Rome as if he had been there. Alan谈起罗马来就好像他去过那里似的。
How I wish we students had more free time to relax ourselves! 我们学生多么希望有更多的自由时间放松自己！
I failed in the maths exam. How I wish I hadnt wasted so much time playing!
What a pity you cant go to the party. How I wish I could dance with you at the party!
Its high/about time that somebody did (should do) (should通常不省略) 早就该
Its time that you went to school.= Its time that you should go to school.
Its high time that we did something to improve our environment. 该是我们为环保做些事情了。
I think its high time that she made up her mind. 我想她该拿定主意了。
could have done 本来可以（表示过去没有实现的可能）。
might have done 本来可能；本来应该或可以做某事（实际没有发生；含有轻微的责备语气。
should/ought to have done 本来该做某事（而实际未做）
should not/ought not to have done 本来不该做（实际却做过了，含有责备语气）
neednt have done 本来不必做（但是已经做过了）
would rather have done 当时宁愿做了某事（实际没有做过）；否定式would rather not have done表达相反意思，两者都有表示后悔之意。
as, though, although引导的让步状语从句。
1. Although/Though Im young, I already know what career I want to follow.
Young as/though I am, I already know what career I want to follow.
2. Although/Though I respect him very much, I cannot agree with his idea.
Much as/though I respect him, I cannot agree with his idea. 虽然我很尊重他，但是我不同意他的观点。
3. Although/Though he is a child, he knows a lot of Chinese characters.
Child（省略冠词）as/though he is, he knows a lot of Chinese characters. 他虽然还是个孩子，却认识了许多汉字。
4. Although he tried, he couldnt solve the problem.
Try as he might, he couldnt solve the problem. 尽管他努力了，但是他没有解决问题。
5. Although it is raining, Im going out for a walk.
Raining as it is, Im going out for a walk. 天虽然在下雨，我还是要出去散步。
6. Strange as it may seem, nobody was injured in the accident. 这次意外虽然显得不可思议，却没有人受伤。
7. Much as I would like to help, I have a lot to do. 虽然我很想帮助你，但是我有很多事要做。
8. Object as you may, I will go. 纵使你反对，我也要去。