require(d)
1.The rule requires (of) all the clerks to arrive at the office by two o'clock和The Minister requires (of) you to attend a special conference to be held on Monday等句子里的of用的少，不用的多。用了of，那requires把不定式to arrive和to attend作宾语，of all the clerks和of you都是状语短语，所以不可说All the clerks are required of to arrive at the office by two o'clock和You are required of to attend a special conference to be held on Monday，该把of删去。
上面两句里的requires都作orders或commands解，只用在正式文字里。
2.require后面的以that引导的从句里用shall或should。例如：The rule requires that all the clerks shall（或should）arrive at the office by two o'clock.和The rule required that all the clerks should arrive at the office by two o'clock.也往往用虚拟现在式。例如：We require that each of you reply（不用replies）promptly.和We required that each of you reply（不用replied）promptly.
3.He required an apology of her和This is all that is required of you等句子里的of不可改作from。
4.require后面的动名词一定属于主动语态，但在意思上一定是被动的。例如：
- The dog will require watching.
- The whole place requires cleaning.
- The baby requires looking after.
- The matter requires thinking over.
假使把动名词改作不定式，必须用被动语态。例如：
- The dog will require to be watched.
- The whole place requires to be cleaned.
- The baby requires to be looked after.
- The matter requires to be thought over.
5.require的宾语后面有时接过去分词。例如：The storm required all the windows closed.
6.required course（必修科）和required subject是美国英语。在英国通常不用required而用compulsory或prescribed。
