Question marks ?

The question mark is punctuation that signals a query. For the most part, its use for a direct question at the end of a sentence is straightforward. It becomes more complex when writing:

  • an indirect question
  • a polite request
  • a rhetorical question.
Direct and indirect questions
Use when you pose a direct question that needs a response, but not for a statement that incorporates a question
What criteria should we use?
Ask yourself how can you use existing resources before setting the budget.

When you ask a direct question, end the sentence with a question mark rather than a full stop.

A direct question might begin with:

  • a ‘wh’ word, such as ‘who’, ‘what’, ‘why’, ‘how’, ‘where’ or ‘when’
  • an auxiliary verb, such as ‘am’, ‘are’, ‘is’, ‘was’, ‘were’, ‘have’, ‘has’, ‘had’, ‘do’, ‘does’ or ‘did’
  • a modal verb, such as ‘will’, ‘would’, ‘can’, ‘could’, ‘shall’, ‘should’, ‘may’ or ‘must’.

Used at the start of a sentence, these all signal a question and are known as interrogative words.

Where is the proposed development site?
Do you know how much it will cost?
Would you like to attend the meeting?

You don’t need a question mark after a statement that doesn’t ask a direct question, even if it includes interrogative words.

Consider what the community response will be if this project goes ahead.
The client will want to know why the deadline has changed and when we will now deliver the project.
But if you add an interrogative tag to the end of a statement, add a question mark as well.

You’ll be at the conference, won’t you?

Polite requests
Avoid with questions that seek an action rather than a response to the question itself
Please could you let us know your thoughts about the memo.

Similarly, you do not need a question mark where you are not asking the reader for a direct response to a question. This will mostly be because you are requesting an action rather than an answer, but framing it in question form for politeness.

In these cases, use of a question mark can sound more aggressive and even cast doubt on whether you expect the reader will comply.

I think we’ll need a few days to review the quotes, so perhaps we meet later in the week.

I think we’ll need a few days to review the quotes, so perhaps we meet later in the week?

Rhetorical questions
Use when a response is already known rather than a genuine question
We got that wrong again? 
What could he have done differently? we asked.
A rhetorical question is where the writer already knows the answer but is emphasising the expected response by framing it as a question. These are more common in speech, so take care before using them in formal writing. They can sound aggressive or sarcastic. 
The numbers in your timesheet were incorrect?
Did our manager get to the meeting on time again? 

A less common conundrum is how to punctuate a rhetorical question where it falls inside a sentence that is then attributed to a speaker. You can add a question mark and continue the sentence without any carriage punctuation such as commas. 

And where will we will get the budget from? she posed to no-one in particular.