mean to do　 打算、想，mean doing　意味着。例如：

I mean to go, but my father would not allow me to. 我想去，但是我父亲不肯让我去。

To raise wage means increasing purchasing power. 增加工资意味着增加购买力。

8.11 begin(start) doing/to do

begin / start to do sth /begin / start doing sth.

1)谈及一项长期活动或开始一种习惯时，使用doing。例如：

How old were you when you first started playing the piano? 你几岁时开始弹钢琴?

2)begin, start用进行时时，后面动词用不定式to do。例如：

I was beginning to get angry。我开始生起气来。

3)在attempt, intend, begin, start 后接know, understand, realize这类动词时，常用不定式to do。例如：

I begin to understand the truth。我开始明白真相。

4)事物作主语时。例如：

The snow began to melt.雪开始融化了

8.12 感官动词 + doing/to do

感官动词 see, watch, observe, notice, look at, hear, listen to, smell, taste, feel + do表示动作的完整性，+doing 表示动作的进行性。例如：

I saw him work in the garden yesterday. 昨天我看见他在花园里干活了。(强调"我看见了"这个事实)

I saw him working in the garden yesterday.(强调"我见他正干活"这个动作)昨天我见他正在花园里干活。

典型例题

1)They knew her very well. They had seen her ___ up from childhood.

A. grow　 B. grew　 C. was growing　 D. to grow

答案：A。因题意为，他们看着她长大，因此强调的是成长的过程，而非正在长的动作，因此用see sb do sth 的句型。

2)The missing boy was last seen ___ near the river.

A. playing　 B. to be playing　　C. play　　D. to play

答案A. 本题强调其动作，正在河边玩，应此用see sb. doing sth句型。