Guide to Grammar and Usage 298 Examples:Lisa's book, Jillian's manuscript, women's room, men's room Use an apostrophe to show that letters have been left out of contractions. Examples:can't, won't, I'll Q Question Marks See Punctuation. Quotation Marks See Punctuation. R Run-On Sentences A run-on sentence is two incorrectly joined sentences. Example:The teacher walked into the room there was a mouse in her desk. You can correct a run-on sentence four ways: · Separate the run-on into two sentences.