Single quotation marks are primarily used in the following cases:
- Quoting within a quote: Single quotes are used to enclose a quotation that appears inside another quotation, to distinguish the inner quote from the outer one.
- Example: He said, "I heard her say, 'I will be late.'"
- Titles of short works within quotes: When mentioning the title of a short work (e.g., a poem, song, or chapter) inside a quote, single quotation marks are used.
- Example: "In the poem 'The Road Not Taken,' the speaker reflects on choices."
- Emphasis or special use of words: Single quotes can be used to highlight or emphasize a word or phrase, often to show irony or distance.
- Example: The so-called 'expert' was wrong.
- In headlines: Single quotation marks appear in headlines when quoting a phrase or title.
The most common setting, particularly in American English, is the use of single quotes to mark a quote within a quote, helping to maintain clarity by alternating between double and single quotation marks. In contrast, double quotation marks are used for direct quotations or speech, enclosing most titles of short works unless nested inside another quote. These rules can vary somewhat depending on style guides or regional conventions (e.g., British English may use single quotes more frequently for direct speech), but the role of single quotes as nested quotation marks or in highlighted contexts is standard.
