在表示建議、命令、要求、忠告等動詞的后面，其賓語從句的謂語用“should+動詞原形”表示虛擬語氣

常用的此類動詞有：

表示“要求”的：ask, desire, request, demand, require, beg

表示“提議、勸告、建議”的：move, prpose, suggest, recommend, advise, vote

表示“決定、命令”的：decide, order

表示“主張”的：maintain, urge

表示“同意、堅持”的：consent, insist

例：The doctor suggested that he (should) try to lose his weight.

He insisted that we (should ) tell him the news.

上述動詞的名詞形式，demand, desire, requirment, advice, order, decision, recommendation, suggestion, 以及necessity, preference, plan, motion, idea等名詞，其后的表語從句或同位語從句，也用“should+動詞原形“表示虛擬語氣。現代英語，特別是美國英語，常省去“should”，例：

The advice is that we (should) leave at once.

He idea that we (should)visit Great Wall was warmly welcomed.