外教一对一
不定式to在什么情况下可以省略
1. 当and或or连接两个并列不定式时，第二个to常省。

I plan to call him and discuss this question.
我计划给他打电话，讨论一下这个问题。

My friend in China asked me to telephone or write to her in my free time.
我中国的朋友让我有空给她打电话或写信。

2. 当两个并列to有对比意义，第二个to不能省。

I haven’t decided to stay at home or to travel to Beijing this holiday.
我还没决定假期是待在家里还是去北京旅行。

To be, or not to be, that is the question.
生存还是毁灭，这是一个值得思考的问题。

(《哈姆雷特》)
3. 当两个to之间无并列连词，to不可省。

I came here not to help you, but to fright you.
我来这不是为了帮你，而是为了吓唬你。

4. 当三个或以上带to不定式构成排比，所有to不可省。

外教一对一
Read not to contradict or confute; nor to believe and take for granted; not to find talk and discourse; but to weigh and consider.。