Commas are used to set off the “he said/she said” clause. The comma always goes before the quotation marks.

Incorrect: Henrietta asked “Do you want to go with me?”
(Comma must set off “she said” clause.)
Incorrect: Henrietta asked”,Do you want to go with me?”
(Comma must go before quotation mark.)

Correct: Henrietta asked,”Do you want to go with me?”

Incorrect: “I will go with you”,Jane replied.
(Comma must go before quotation mark.)

Correct: “I will go with you,”Jane replied.

Correct: “Anyway,” she said, “I have to go.”
(Note the pattern when the clause is in the middle.)

A comma is not used to set off a “he said/she said” clause if the part of the quotation preceding the clause ends with a question mark or exclamation point.

Incorrect: “Why did you do that?,” he asked.
(Comma not necessary)
Correct: “Why did you do that?” he asked.

Correct: “Hey!” he screamed. “Come back here!”
(Note that the question mark or exclamation point goes with the quotation, not with the “he said/she said” clause.)