Of course (adv)
1. used to say ‘yes’ or to give someone permission to do something:
May I have a look at your newspaper?” “Of course you can.”
2. used to show that what you are saying is obvious or already known:
The Second World War ended, of course, in 1945.
3. used to show that a situation or a piece of information is not surprising:
We arrived at the restaurant 30 minutes late so, of course, our reservation had been cancelled.