Should I put a period before or after quotation marks?

Typically, a period goes before the ending quotation marks in American English.

Periods with quotation marks examples (American English)
The principal said the teacher was “an exemplar of the profession.”

She told me, “If I leave, I’m never coming back.”

However, in British English, the period only goes inside the quotation marks if the quotation itself is a full sentence. Otherwise, it goes outside. Additionally, British English typically uses single quotation marks instead of double.

Periods with quotation marks examples (American English)
The principal said the teacher was ‘an exemplar of the profession’.

She told me, ‘If I leave, I’m never coming back.’

Try QuillBot’s free Grammar Checker to make sure you’re using punctuation correctly.