How to use the question mark ?

There are two uses of the question mark:

At the end of a direct question [Do you understand this rule?]

To show that something is uncertain (when it should be inside round brackets or parentheses) [He was born in 1886(?) and died in 1942.]

Note: A question mark should not be used at the end of an indirect question in which the speaker’s exact words are not repeated.

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