[语法初识]

原句感知 自主探究 ①... a mass campaign has been started to help solve it.

②The wind is sometimes strong enough to move sand dunes.

③The storms sometimes continue all day and traffic moves very slowly because the thick dust makes it difficult to see.

④Weather experts advise people not to go out.

⑤It is difficult to breathe and the dust makes me ill.

⑥To prevent it coming nearer，the government is planting trees.

⑦I can do nothing but wait at home.

⑧She has no choice but to give in. 1.由句①～⑥可知，不定式在句中分别作宾语、状语、宾语、宾补、主语、状语。

2．由句④可知，不定式的否定式为not to do。3.由句③⑤可知，不定式作主语或宾语时，可用it作形式主语或形式宾语，而把动词不定式放到后边。

4．由句⑦⑧可知，不定式在介词but后时，如果but之前有实义动词do时，则but后的不定式省去to，否则带to。 　　

　　[语法剖析]

语法点一 动词不定式 　　1.动词不定式的时态和语态形式

　　　语态

时态　　　 主动 被动 一般式 to do to be done 进行式 to be doing － 完成式 to have done to have been done 　　(1)动词不定式的一般式：表示与主动词处于同一时间层面或动作发生于主动词之后。

I hope to see you next week.