and與or

and與or

1. 是否定句之后通常用 or 代替 and。如

He spoke loudly and clearly. 他說話聲間宏這且清晰。

He didn’t speak loudly or clearly. 他說話聲音不大且不清晰。

2. 祈使句＋and =if，而祈使句＋or = unless. 如

Work hard, and you will succeed. (=If you work hard, you’ll succeed.) 努力工作，你就會(huì)成功。

Work hard, or you won’t succeed. (＝Unless you work hard, you won’t succeed. )　努力工作，否則你就不會(huì)成功。

3. 有時(shí) and 與 or 可換，如：life and / or death (生死)；有時(shí) and no 與 or 互換。如

He has no brothers and no sisters = He has no brothers or sisters. 他沒有兄弟姐妹。

4. 在選擇疑問句中，用 or 不用 and。如

Is it a pen or a pencil?　那是鋼筆還是鉛筆？

Which is bigger, the sun or the earth? 太陽和地球哪個(gè)大？

5. 在 both 之后用 and，在 either 之后用 or。如

Both you and he are right. 你和他都是對(duì)的。

Either you or he is right. 不是你對(duì)就是他對(duì)。