We have a kitchen faucet about 5 years old installed in a rental apartment. We got a call from the tenant today saying it does not work. No other apartments are having issues. She said she did not touch the shut-off valves. Anybody have a clue what this could be?

Check the shutoff valve anyway.. particularly if she's got kids. Then check the aerator, though I highly doubt a lot of debris would sudenly clog only hers up.

If you have neither hot or cold water coming out of the faucet, remove the aerator on the end of the spout and see if you get water. If you get water with the aerator removed, replace the aerator.

Thanks guys. It turned out that the aerator was missing (the screen rotted out--we have acid water) and after unscrewing the body of the aerator, gunk came out so the faucet works well now. The tenant did have the hot water side turned off, which she didn't tell me at first. Yah never know.