4.56 USAGE NOTE

Note that if the verb is already shortened and added to its subject, you cannot shorten 'not' to '-n't'. This means, for example, that you can shorten 'she is not' to 'she isn't' or 'she's not', but not to 'she'sn't'.

• It isn't easy.
• It's not easy.
• I haven't had time.
• I've not had time.

Note that you cannot add '-n't' to 'am'. You can only use 'I'm not' as the shortened form.

• I'm not excited.

The form 'aren't I' is used in questions. For more information, see paragraph 10.125.

In questions, 'not' is usually shortened to '-n't' and added to the first verb in the verb group.

• Didn't she win at the Olympics?
• Hasn't he put on weight?

However, in formal English, it is also possible to put 'not' after the subject.

• Did he not have brothers?
• Was it not rather absurd?