形容詞直接用的時(shí)候也是比較多的,如
a good idea 形容詞做定語(yǔ).
He is very strong.形容詞做表語(yǔ).
Rainy days make me sad.形容詞做賓補(bǔ).
The room was found dirty.形容詞做主補(bǔ).
你說(shuō)的形容詞前加to be應(yīng)該是不定式的用法.因?yàn)閯?dòng)詞不定式是由to +動(dòng)詞原形構(gòu)成的.它不能直接加形容詞,而形容詞多和be動(dòng)詞連用,所以成了to be +adj.結(jié)構(gòu).
如The teacher asked the students to be quiet.
另外,to+be+adj前常加系動(dòng)詞,例如look,seem等
如：seem to be nervous,看起來(lái)很緊張.