Student or Learner
The following sentence comes from Martin Hewings' ADVANCED GRAMMAR IN USE:
Ray told me that someone had bought the old house next door. Could/ Might (Might would be rather formal here) he be right about that, I wondered.
Could you tell me why we have 'Could/ Might he be right about that' rather than 'He could/might be right about that' in this sentence? If it is a question for the reason of the phrase 'I wondered', then why isn't the question mark "?" used?
It is because it is in the form of a question that she is asking to herself.
Could/ Might he be right about that, I wondered.
You use a question mark whenever the sentence itself asks a question. For instance, you don't put a question mark in after a rhetorical question, because an answer is not really wanted. And you wouldn't but one in in a sentence like this one:
George wondered whether he had made a mistake in punctuation.
Because even though George has a question, the sentence itself is a statement of that fact, rather than a query.
On the other hand, in dialog (internal or external) a sentence that would otherwise be a statement could be turned into a question, complete with question mark, in order to indicate doubt or disbelief.
"Who did it?"
"George did it."
"George did it?"