you should do sth是过去式吗

you should do sth you should do sth是过去式吗 是should to do sth 还是 should do sth? You should do sth?怎么造句 一个英文单词“to tell sb what you think they should do后面是 to do sth should do sth. should to do sth还是should do sth suggest sb.(should) do sth. Would you please do sth 是 help,open的过去分词是什么?是before sb do sth.还是before sb doing sth... 虚拟语气 ifif引导的虚拟语气,从句时态倒退一步吗?主句呢?在对过去进行虚拟时,是不是 if sb had done sth ,sb should have done sth?对现在的虚拟,是不是 if sb did sth,sb should do sth 对将来的虚拟是怎样的? 是You would better to do sth还是you would better do sth 提问句型 是You'd better do sth还是You'd better to do sth you'd=_____you'd是do sth还是to do sth.you’d反义词是什么? you'd=_____you'd是do sth还是to do sth.you’d反义词是什么 should do sth=be ____ ____ do sth it can help you是do sth是to do sth, 句子could you asked sb.to do sth.中为什么could 后面ask是过去时,could后面动词不是原型么?同上