Direct questions always take question marks: Who is going with you? Did he ask you if you were going? Indirect questions never take question marks: He would like to know who's going with you. For multiple questions, either use a single question mark at the end of the complete sentence: Did she plan the project, manage the budget and supervise the staff? Or stress each element by breaking up the sentence: Did she plan the project? Manage the budget? Supervise the staff? Put only one space after a question mark (and other sentence-ending punctuation).

The question mark replaces the comma normally used when attributing a quotation: "Who is going?" she asked. The question mark may go inside or outside quotation marks depending on the meaning: Who wrote "Everybody's Got Something to Hide Except Me and My Monkey"? She asked, "How long will it take?" Also, use a single question mark, inside the quotation mark, in sentences like this: Did you hear him say, "Who wrote all the reports?"