Using English

[Dinhtuong]

Could you please tell me the usage of :
- sure.
- of course.
-certainly.

Are they the same meaning?
which is more popular in conversation?

[Rover_KE]

In what context do you want to use these words?

Try entering Sure/of course/certainly into the Search box at the top of the page for links to other discussions of the topic.

Rover

[virus99]

Of course, there is a difference. That's for sure. Certainly, you will find out about their meaning and usage:

certainly - definition of certainly by Macmillan Dictionary
of course - definition of of course by Macmillan Dictionary
sure - definition of sure by Macmillan Dictionary