注：若enough前出現否定詞，則不僅否定了enough，而且也否定其后的不定式：He was not strong enough to do the work. 他不夠強壯，不能做這工作。
另外，該句型有時可與so [such]…that結構轉換：
He is rich enough to buy a plane. 他很有錢，可以買一架飛機。
→He is so rich that he can buy a plane. 他很有錢，可以買一架飛機。
有時該句型也可與too…to句型轉換：
He is too young to go to school. 他太小，還不能上學。
→He is not old enough to go to school. 他還不夠大，還不能上學。
enough作形容詞，意思是"足夠的;充分的"，常與for或不定式連用，可以作定語或表語。作定語置于被修飾的名詞前后均可，前置時強調enough，后置時強調被修飾詞。
例句：So what is good enough for you? 所以什么對你來說是足夠好呢？