I hope to meet him soon.

（3）宾语补足语：

They expected us to help them.

Hewants his son to study hard.

金牌重点：

不定式作宾补，如谓语动词是感官动词，使役性动词（see, hear, notice, watch, make, have, let...），则不定式符号“to”须省略，但在被动语态中不能省。

I heard them sing in the classroom.

I made her clean the room.

The girl is heard to sing an English song.

（4）用作表语：To teach is to learn.

His job is to sell cars.

（5）用作状语，表示目的，结果。

We come to school to study English.（目的）

           = in order to

I hurried to the store, only to find it closed.（结果）

（6）定语：不定式短语作定语须位于名词之后。

He asked for a piece of paper to write it on.

= to write it on the piece of paper. liuxuepaper.com