The answer to 'drain not working' is that a clogged drain is a common plumbing problem with several potential causes. Symptoms include slow draining, standing water, or a complete blockage. Some common causes include hair, soap scum, food debris, or foreign objects accumulating in the drain over time.
For minor clogs, you may be able to clear the drain yourself using a plunger, drain snake, or chemical drain cleaner. However, for more serious blockages or if the problem persists, it's best to call in a professional plumber. They have the tools and expertise to properly diagnose and fix the issue, preventing further damage to your plumbing system.