动词不定式 “to do” 是英语中最常见的结构之一，它用法灵活多样，令不少英语学习者困惑不已。

用法总结

1 我们可以在形容词后加上不定式 “to do”，即：形容词 + 不定式 “to do”。 

It's easy to learn English with the BBC.

We're always happy to help!

It's fun to spend time with friends.

That's hard to say.

2 我们可以用不定式 “to do” 表示做某事的目的或理由。

I went to the shops to buy some milk. 

I am working to save money.

Don't make that face to scare him! 

Join us on social media to learn more English.

3 我们可以在量词后使用不定式 “to do”，结构是：量词 + 名词 + 不定式 “to do”。

I have too many emails to send.

There isn't enough time to get to the station.

There are few pencils left in the studio to draw blueprints with.