This is a very common problem that can be fixed in one of three ways: by cleaning the aerator at the tip of the faucet spout, by checking/changing the faucet valve gasket(s) or by replacing the nipples (short pipes) that protrude through the wall beneath the sink. The first thing you should check is the faucet spout. Unscrew the aerator tip to remove it and turn on the water. If water comes out it means your culprit is a clogged aerator. Clean it with vinegar and a toothbrush. If the aerator isn't the problem then the next step would be to remove the valve stems to see if the gaskets inside are preventing the free flow of water. For detailed instructions and a picture type "faucet repair" into the search engine. If your investigation of the faucet proves fruitless and nothing looks clogged then it's time to scrutinize the nipples that come out of the wall. The nipples are connected to angle stops (shut-off valves) that reside below the sink and against the wall. The nipples and the shut-off valves are almost always made of different materials. Electrolysis occurs when dissimilar metals are in contact and the resultant corrosion can completely clog the inside of a nipple. We have no idea why the valve always seems to skate through unscaved. Any way, shut off the main water valve, remove the shut off valves, remove and replace the nipples with modern Teflon coated nipples (they won't corrode because the prevent electrolysis from occurring) and put everything back the way you found it. WARNING: The fittings and pipes in the wall could possibly be corroded as well. This means that the project could turn out to be a really big job. Be prepared for possibility and keep in mind that most of the time the job is reasonably simple. And, good luck!