To correctly use commas to set off nonessential information in a sentence, you should place commas before and after the nonessential clause or phrase. Nonessential information adds detail but can be removed without changing the fundamental meaning of the sentence.
Here are some examples:
- My brother, who lives in New York, is visiting us next week.
- The book, which I borrowed from the library, is fascinating.
- The car, a vintage model, needs some repairs.
In these examples, the phrases in the commas provide extra information but are not necessary for the sentence to make sense. If you have a specific sentence in mind that you'd like help with, feel free to share it!