1 用作目的状语。
He has gone to Shanghai to look for a job. 他去上海找工作了。
She studied hard to pass the exam. 她刻苦学习,以便能通过考试。
2 用作程度状语。
This book is easy to read . 这本书容易读。
The work is difficult to do . 这项工作难做。
3 用作结果状语。
The girl is too young to look after herself. 这个女孩太小,不能照顾自己。
The tree is too tall for him to climb . 这棵树太高,他爬不上去。