Kitchen sink won't drain

There are a few things you can attempt to fix the problem if your kitchen sink is not draining:

See whether there are any foreign things in the garbage disposal that might be preventing water from flowing. If any, get rid of them.
Look for any obstructions in the P-trap, which is the curved pipe under the sink that links to the drain. To accomplish this, set a bucket below the P-trap and take it out of the pipe.
If the P-trap is clean, look for any obstructions in the line that connects the sink to the main drain.
If there are no clogs to be found and the sink still won't drain, there might be an issue with the main drain. It will be necessary to hire a qualified plumber for this.
When attempting to clear a blockage or take out the P-trap, extreme caution must be taken. It is preferable to call a licenced plumber for help if you are unsure of how to complete this securely.