When do you use single and double quotients

Answer:In common usage, there may be a distinction between the single and double quotation marks in this context; often, single quotation marks are used to embrace single characters, while double quotation marks enclose whole words or phrases[.] Emphasis mine.

Single quotation marks are used when you're quoting someone within a double quotation.

Double quotation marks are used for: direct quotations, and Titles