Question

后置定语和目的状语如何区分

He was a brave man to do what he did。这句话如何翻译？do what he did这边怎么理解意思？
i am looking for a room to live in （是后置定语还是目的状语）我在网上看到是后置定语，我认为把它理解成目的状语是不是也可以----我正在寻找房间的目的是来住。
i buy some food to eat 像这句话（我买一些食物是来吃）

Answer 1

意思是He was a brave man, and he did something that had been done by him.
可以理解为He was a brave man to do those things. [those things]是他已经做的那些事。
他所做的那些事证明他是个勇敢的人。

a room to live in 后置定语，我在寻找一个可供我住"的"房间, 是修饰这个房间。

这里to live in 只可能修饰 room, 不能修饰谓语。如果说我为了居住而寻找，其实寻找的还是房间这个名词，一个住人的房间，于是又回到了定语的位置。

some food to eat 这里确实是目的状语。to eat是修饰谓语buy, I buy to eat.

一个简陋的区分方法是，如果能翻译成"...的+宾语“，那这部分就是做定语。
例如上句就不能翻译成，我买了一些”供吃的“食物。

如果去掉to do，意思不完整，那是作宾补。

如果不是以上两种，且to do 和宾语并没有直接修饰关系，而与主语有目的、结果等关联时，作状语。

追问

He was a brave man to do what he did可以是这里to do 不是不定式么？to do 不是表示还没做的事情。我会误解成为他会去做他做过的事情

追答

因为主句是过去式 He was...

比如，You were kind to treat me like a friend in the party. 这里说的treat me是指已经发生过的事情。
He was a free man to do as he pleased. = He was a free man,
and he did everything he wanted.

追问

He was a brave man, and he did something that had been done by him.
he did something这个是不是就表示代表这句话里的to do what
what he did为什么这边就转换成被动语态了that had been done by him

追答

是的，to do what he did = something he did
因为，something he did = something that had been done by him
前一句something做宾语，something he did -> he did something
后一句something 做主语，something had been done.