Do you have a clogged sink? Do you not know what is wrong with it? Use this guide to solve your problem. If your sink becomes unclogged after step 1 or step 6, then you do not need to continue following the guide. But it is highly recommended that you finish the guide completely to ensure your sink is completely unclogged.
Begin by filling the sink halfway full with water.
Pump the plunger rapidly for 30 seconds.
Do NOT break seal between plunger and drain.
Repeat this process 4 to 6 times.
Wait 20 min before proceeding to the next step. This will allow some debris to flow down the pipes.
If the sink is equipped with a spillover (a hole in the side wall, next to the top edge), you should cover it with a paper towel or kitchen towel while pumping the plunger with the other hand. Otherwise the pressure, that you create by pumping, would be released via the spillover immediately, possibly throwing dirt into your sink.
If you wish to pump with both hands, you may want to ask somebody for help, to cover the spillover.