Inactive Tutor answered 03/16/19
Hello Lacie,
this depends entirely on whether the sentence is formatted as a question, or a statement. If something is simply being declared, it is incorrect to use a question mark. However, if by inflection you mean that the character is questioning something or is expressing uncertainty, then it is totally fine to use a question mark.
Feel free to contact me if you need tutoring in the future.
-Andrew