Grammar Tips. Comma 8.

A comma is used to set off introductory words to a sentence.

INCORRECT: Yes it was a beautiful wedding.

CORRECT: Yes, it was a beautiful wedding.

CORRECT: No, we won’t be attending the party.

CORRECT: Honestly, I don’t know the answer to that.

INCORRECT: In my opinion he was making a huge mistake.

CORRECT: In my opinion, he was making a huge mistake.