When Do We Use A Question Mark?

Core rule: use a question mark for direct questions

Use a question mark at the end of a sentence that asks a genuine, spoken-style question. This typically means the sentence requests information or action and would begin with who, what, when, where, why, how, which, or can/could/will/would/should. The question mark replaces the period as the closing terminal mark.

Examples include:

• What time does the meeting start?
• Could you send me the report when you have a moment?
• Why did the project succeed this quarter?

Indirect questions do not take a question mark

When a question is embedded as an indirect or reported clause, it functions as a statement and ends with a period. Indirect questions are common in formal writing and polite requests.

• Direct: Where is the nearest subway station?
• Indirect: I am asking where the nearest subway station is.
• Direct: Can you finish this by Friday?
• Indirect: She wondered whether he could finish this by Friday.

Polite requests and soft questions still require a question mark

Polite or soft questions that frame a request as a question should still end with a question mark. These constructions seek cooperation rather than a literal answer.

• Would you mind signing here?
• Could we possibly move this to Tuesday?
• Is it possible to extend the deadline?

Tag questions need a question mark

Tag questions are short clauses added to a statement to seek confirmation. The terminal punctuation is always a question mark, even when the statement itself could end in a period or exclamation point.

• The report is finalized, isn’t it?
• You will be joining us, won’t you?
• This option seems acceptable, doesn’t it?

Avoid stacking question marks or combining with other strong marks

Formal writing calls for a single question mark at the end of the sentence. Exclamation points and multiple question marks are generally unnecessary and reduce professionalism.

• Acceptable: Why hasn’t this been submitted yet?
• Avoid: Why hasn’t this been submitted yet?! or What is this???

Periods and exclamation points in quoted questions

When the entire sentence is a question, place the question mark inside quotation marks if the quote is a direct question and the attribution follows. Place it outside if the sentence itself is not a question but contains a quoted question.

• She asked, "Where is the invoice?"
• "Where is the invoice?" she asked.
• He wondered whether she said "where is the invoice."

Question marks in titles and headings

In titles and headings, question marks can be used to frame a direct question, which may affect search appearance and click-through behavior. Ensure that the question clearly reflects user intent and includes keywords relevant to the topic.

• Effective: How to Optimize Images for Web Performance?
• Also acceptable: Optimizing Images for Web Performance

Use a question mark with caution in very long or multi-clause sentences

When a sentence contains multiple clauses, consider whether it truly functions as one question or as multiple questions. If multiple questions are intended, they can be separated or listed, and each may require its own question mark for clarity.

Examples of clarity choices

Wordy: Why did the vendor delay the shipment and was there any notice provided?

Clearer: Why did the vendor delay the shipment? Was there any notice provided?

Key points at a glance: when to use a question mark at a glance