BBC语法|目的不定式

Infinitives of purpose
目的不定式

1. We use infinitives of purpose to explain why we're doing something:

我们使用目的不定式来解释我们正在做某事的原因：

You're watching this video to get better at speaking English.
您正在观看此视频是为了更好地讲英语。

2. We use for + somebody to explain that we're doing an action on behalf of someone else.

我们用for + somebody来解释我们为了某人的利益进行某项操作。

I make these videos for you to get better at English.
我为您制作这些视频，以帮助您提高英语水平。

3. In more formal English, we use in order (not) to or so as (not) to:

在更正式的英语中，我们用in order (not) to 或者 so as (not) to：

The government has raised taxes so as to / in order to fund the NHS.
政府提高税收以/为NHS提供资金。

He paid the fine in order not to go / so as not to to prison.
为了不去监狱，他付了罚款。

4. We use the infinitive of purpose after a noun, pronoun or indefinite pronoun to explain what we need it for:
   我们在名词，代词或不定代词后的使用目的不定式来说明我们需要这个（名词，代词或不定代词）目的：

I want a house to live in.
我需要一个房子来居住。（to live in 在名词 house后面，表示需要这个House的目的是live in ）