sure和of cousic有什么不同？

sure 是比较随便的说“是啊”“当然”，表示无所谓的态度。
of course 是很认真的说“当然！”

of course: [ əv'kɔ:s ]

当然

例句与用法:
1. I will write to you of course, but not every week.
我当然会写信给你, 但不是每星期都写。

2. Yes, of course you can.
是的，你当然可以。

3. That was 40 years ago, but of course you wouldn't remember it.
那是40年以前的事, 你自然想不起来了.

4. Yes, of course.
是的，当然。

5. Why, of course!
噢，当然可以!

6. Mothers as a matter of course have much affection for their children.
母亲自然地很疼爱孩子。

7. People seem to have drunk far too much tonight, present company excepted of course.
今晚大家似乎喝酒喝得太多了，当然在座的各位除外。

8. Who said I can't cook? ie Of course I can!
谁说我不会做饭?

英英解释:
副词of course:

1. as might be expected
同义词：naturally, course

sure: [ ʃuə ]

a. 确信,必然的,必定的
ad. 当然,确实地,无疑地

词形变化:
形容词比