Why are my single and double quotes appearing as question marks?

The most common cause of this issue is copy/pasting information from Microsoft Word.

Microsoft Word automatically converts a number of character types, including changing straight quotation marks ( ' or " ) to curly (smart, or typographer's) quotes as you type.

To disable the smart quotes and use regular quotes instead, in the Tools menu, click AutoCorrect, and then click the AutoFormat As You Type tab.

Under Replace as you type, uncheck the box for "Straight quotes" with "smart quotes".