When you use quotation marks, put periods and commas inside the closing quotation mark.

Hillel’s first two questions contain an unusual use of “for.”

However, where you are giving a parenthetical in-text citation for the source you are quoting, the punctuation goes after the citation (except with block quotations):

According to the New Yorker article, an FBI forensic linguist cracked the Unabomber case “by analyzing syntax, word choice, and other linguistic patterns” (25).

For more on citing sources, see Chapters 21 and 22.

Put question marks and exclamation points inside the quotation marks only if they’re part of the quotation itself:

Hillel’s third question is “If not now, when?”

Are you surprised that the Unabomber’s manifesto includes the words “chimerical” and “anomic”?