时间状语从句和省略

时间状语从句和省略

一、时间状语从句

1. 某些易用错的连词。

(1) 连词immediately / directly / instantly和词组the moment, the minute意为“一……就……”，相当于as soon as。如：

The thief ran away the moment / directly he saw the policeman.

[注意]

a. immediately / directly / instantly也是副词，在句中作状语。如：

I didn’t immediately realize how serious the situation was.

b. 介词on / upon +名词/ V-ing也表示“一……就……”。如：

Yao Ming was surrounded by the media on his arrival at the airport.

On seeing the painting by Van Gogh, I fell in love with it at once.

(2) 词组the first time, the last time, each time, every time以及by the time，都引导时间状语从句。如：

The first time I spoke English before foreigners, I was a student of high school.

Every time I meet the policeman at that crossroads, he will give me a big smile.

[注意] for the first time是介词短语，意为“第一次……”，常用来作状语。

They had a face-to-face talk for the first time.

(3) when, while和as引导时间状语从句的区别：

when引导时间状语从句时，可与短暂性动词连用，也可与延续性动词连用；而

while只能与延续性动词连用；as表示两个动作的同时性，意为“一边……，一边……”。如：

When I entered the classroom, all the students looked up at me curiously.

Could you look after Robert while I am preparing the report?

The children sang as they climbed the mountain.

2. 时间状语从句中的时态。

(1) when, as soon as, every time, immediately, the moment等在引导时间状语从句时，若从句用一般现在时，主句用一般将来时。如：

The moment I finish my homework, I will go out to play football.

(2) 在It / This / That is the first / second / last time that…中，that从句中的谓语动词用现在完成时；而It / This / That was the first / second / last time that…中，that从句中的谓语动词用过去完成时。如：

This is the first time that I have visited the Great Wall.

That was the second time that he had been interrupted by the noise outside.

二、省略

1. 状语从句中的省略。

(1) 连词when, while, if, as, though / although, until, once, whether, unless, where等引导的状语从句中，当主句的主语和从句的主语一致时，常省略跟主句相同的主语和be，只剩下主要的部分。如：

While / When (you are) crossing the street, you must be careful.

Unless (I am) invited to attend the party, I won’t go to his house.

(2) 当出现when, if, where, wherever, whenever, than等后直接接possible, necessary时，可理解为省略了“it + be的适当形式”。类似的还有：if so, if not, if some, if any, if ever等。如：

Please call me up if (it is) necessary. I relax with a good book whenever (it is) possible.

2. 不定式结构中的省略。

在同一个句子或紧密联系的对话中，为了避免重复，作宾语或补足语的不定式再次出现时，不定式符号后面的内容常被省略，只保留不定式符号。常用于refuse, would like / love, wish, want, mean, expect, hope, intend以及afraid, happy, glad, willing, ready等后。如：

Susan’s parents didn’t allow her to travel alone in Tibet, but she still hoped to (travel alone in Tibet).

[注意] 当to后是be或have 时，be与have 不能省略。如：