当然用英语怎么说?

Sure, in English it is pronounced as "Of course".

It is an adverb phrase that originated from Middle English. It is used to indicate that the speaker thinks something is self-evident or to show agreement with a statement.

Here are some example sentences:

Of course I will come to your party.
"Do you want to go to the movies?" "Of course!"

In these examples, the speaker is showing agreement with the statement or question being made.