动词不定式做目的状语和做后置,定语时怎么区分例句1 The subjects took a fifty-question test to see which words they remember.2 Successful learners do not wait for a chance to use the language .

作后置定语是不定式只修饰说明前面名词的.
Successful learners do not wait for a chance 【to use the language】
to use the language 是修饰chance的 ，一个使用语言的机会，而to~与前面的谓语wait没有任何联系。

作状语是修饰整个句子的，表示目的，原因之类。
不定式作状语时，他的逻辑主语应该是句子的主语。
The subjects took a fifty-question test【 to see which words they remember】
subjects 既发出took动作，又是to see~~的逻辑主语.


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例句1 The subjects took a fifty-question test to see which words they remember.
这是不定式做目的状语.
2 Successful learners do not wait for a chance to use the language .
这是不定式做定语
⒈不定式作定语
不定式在句中作定语,置于被修饰的名词或代词之后.如：
①The next train to arrive is from Washington.
②Do you have anything to be taken to your sister?
③Do you have anything to say on the question?
④Would you please give me some paper to write on?
⑤My wish to visit France has come true at last.
不定式短语作定语和被修饰词之间表示以下关系：
(1)表示将来的动作（例①）.
(2)与被修饰词之间有动宾关系,如是不及物动词,则需加介词（例④）.
(3)与被修饰词之间有动宾关系,同时与句中其它词之间又有逻辑上的主谓关系时,尽管有被动含义,却仍 用主动语态（例③）；如只有动宾关系,而无逻辑上的主谓关系,则需用被动语态（例②）.
(4)不定式作定语时,一般可转换为定语从句,例①to arrive=that will arrive.