[误] - Now， I'm back Can I play?
- Perhaps You'd better do your homework first
[正] - Now， I'm back Can I play?
- I'm afraid not You'd better do your homework first
[析] Perhaps 是表示对一种拿不准的事态的推论，如： Am I right? Perhaps而 I'm afraid not 则表达一种不同意的态度。 be afraid 的几种用法有：
I'm afraid that you are right
其后直接加宾语从句。
- Will you come to my birthday party?
- I'm afraid not I have to go to see my father He is in hospital
其后+not，表示否定。
- Sorry， I don't want to go there alone， I'm afraid of the dog
其后+名词，表示对某人，某物的害怕。
Mary is afraid of making mistakes in the exam
其后+ of + 动名词，表示害怕做某事。
Mary is afraid to see the teacher because she didn't do well in the exam
其后+ 不定式，表示不敢去做某事。
