whether

1.下面两句意思相同，第一句比第二句普通：

• I do not know whether he is twenty or twenty-one.
• I do not know whether he is twenty or whether he is twenty-one.

2.下面六句意思相同，第一句最普通：

• I do not know whether he is well or not.
• I do not know whether he is well or no.
• I do not know whether or not he is well.
• I do not know whether or no he is well.
• I do not know whether he is well or whether he is not well.
• I do not know whether he is well or is not well.

whether or no可以作“无论如何”解。例如：Well, I'll come whether or no. （唔，我无论如何要来。）

3.下面三句略有不同：

• I do not know whether he is well or not.
• I do not know whether he is well.
• I do not know whether he is not well.

第一句是“我不知道他身体是否好”。第二句有“我想他身体也许不好”的意思。第三句含有“我想他身体大约并非不好”的意思。比较下面两句：

• I asked him whether he knew her. （我想他并不认识她。）
• I asked him whether he did not know her. （我想他也许认识她。）

4.注意下面第一句里用rains，不用will rain，第二句里用calls和call，不用will call和shall call：

• Whether it rains or not, I will go tonight.
• Whether he calls on us or we call on him tomorrow, we shall talk the matter over.

5.下面每组里的第一句比第二句普通：

• I do not know whether she is married or not.
  I do not know whether she be married or not.
• Whether she is married or not, she is a good housekeeper.
  Whether she be married or not, she is a good housekeeper.

6.the question (of) whether we ought to start today or tomorrow和the problem (of) whether light is matter等表达方式里的of是多余的，最好删去。

7.比较下面每组里的三句：

• He asked his mother: 'May I go to the show?’
  He asked his mother whether he might go to the show.
  He asked his mother might he go to the show.
• He got a note from his sister saymg: 'I am unwell. Can you comeat once?’
  He got a note from his sister saying that she was unwell andasking whether he could come at once.
  He got a note from his sister to say that she was unwell, andcould he come at once.

第一句和第二句都是正常的英语，有人以为第三句不算正当。