weak用法和结构

weak在句中可用作表语，也可用作定语。用作定语时，其后可接具体名词或抽象名词，作表语时，其后可接介词短语、动词不定式或that从句。

例句：

①用作形容词 (adj.)

用作定语: ～+ n.

She spoke in a weak voice.

她有气无力地说话。

②用作表语: S+be+～

Her pulse is weak she must be very ill.

她的脉搏微弱，必定病得很厉害。

③S+be+～+ prep .-phrase

She was weak from a long illness.

她因长期生病而十分虚弱。

④S+be+too ～+to- v

The flu victim was too weak to walk.

这位流感病人虚弱得连路都走不动。

⑤S+be+～+that-clause

The teacher's so weak that the children do what they like.

这老师太软弱了，孩子们因此可以为所欲为。

短语：

weak answer 缺乏说服力的回答

weak character 优柔寡断的性格

weak coffee 淡咖啡

weak constitution 虚弱的体质

weak defence 不牢固的防御工作