(1) ①unfit for指“使不适合”，常指由于健康方面的原因而变得不适合，unfit为及物动词，可用于被动语态。
- She was unfitted for riding a bicycle by her heart condition.
她的心脏状况使她不适合骑自行车。 - Years of work in Africa unfitted him for life in a cold country.
在非洲工作多年使他无法适应在寒冷的国家生活。
②unfitted可用作形容词，作表语。
- I think he is unfitted for this sort of job.
我认为他不适合干这种工作。
(2) be unfit for意为“不适合(做某事)”，其中，unfit为形容词。
- The water in this well is unfit for drinking.
这个井里的水不适合饮用。 - He is unfit for heavy work on account of poor health.
由于健康不佳，他不适于干重活。
(3) be unfit to do意思是“不适合做(某事)”，unfit为形容词。
- He is very weak and still unfit to do heavy work.
他非常虚弱，仍不适于干重活。 - The young boy is unfit to run that business.
这个年轻孩子不适合去经营那项生意。
(4) be unsuitable for指“不适合(某一目的或场合)”，一般指事物，后接名词或动名词、动名词短语。
- That dress is unsuitable for this occasion.
这件衣服不适合在这种场合穿。 - A car without air-conditioning is unsuitable for driving across the desert in such hot weather.
没装空调的车不适合在这样炎热的天气里在沙漠里行驶。
(5) be unsuited for与be unsuitable for意思相同，可换用，与be unfit for在用于物时意思相同。
- The water is unsuited/unfit/unsuitable for drinking.
这水不宜饮用。 - That sort of tool is unsuited for such use.
这种工具不适用于这种用途。
