假設法表遺憾

用假設法表遺憾是老中很弱的地方，因為無法用中文把它翻譯出來，必須靠體會。這種用法牽涉時態，而且非得照規矩用不可，沒有其他方法可以替代。
一個朋友向另一人抱怨，，你怎麼早不把資料送來，害我白寫了。他這樣寫：
You should really send this information to me early. I spent time on my version, and all is in vain.
這是中式寫法，尤其第一句，後面兩句倒還好。
這樣寫更好：
You should have sent this information to me earlier. I have spent a lot of time on my version, but now all is in vain.
凡表示遺憾，如早應該，早知道...都要用should, would, could +現在完成式，死規矩，一定要記得
I should have told you.
I wouldn't have helped you.
Who would have known that the market had crashed in such a short time?