Both queue and cue can be nouns or verbs, so this will be a two-part discussion. Enjoy!
Nouns
The noun queue refers to a group of people (or, for the more fanciful, "entities") who are standing in a line; it can also refer to the line itself in the abstract. It's more commonly used in British English than American.
In contrast, the noun cue typically refers to a prompt or trigger for an action; it can also be a shortened version of cue stick, the stick used for shooting pool or billiards.
So:
Incorrect:
- Right on queue, the cat started yowling.
- I was going to go to the movies tonight, but there was a ridiculous cue for tickets.
Correct:
- Have you seen the queue for security to get into the bar? It's out the door!
- Remember, when you hear the phone ring, that's your cue to open the door.
Verbs
These are pretty easy to remember once you understand the distinction between the nouns. The verb queue is the action of forming a queue or line; the verb cue is the act of prompting an action.
So:
Incorrect:
- We're going to cue for the train.
- I'll queue you when I want you to turn on the lights.
Correct:
- I'm not doing much, just queuing for the show.
- When you're ready for me to come in, cue me.
So there you have it!
And remember: "que" is not an English word ;-)
