A comma may be used correctly to do any of the following: (a) join sentence when used with a conjunction. (b). set off an introductory word,
clause, or phrase. (c) set off interrupting words or expression
Examples:
When he came, his mother ran unto him. Talking about bugs, I don't like any of them. Hey, did you do the thing I told you to do? if you don't know how to answer that, you can ask me for help.
