How can I prevent my Volkswagen Polo from stalling frequently?

I have a used Volkswagen Polo and lately it has been stalling frequently. It usually happens when I come to a stop or when I am idle at a traffic light. What could be causing this issue and how can I prevent it from happening again?

It could be a problem with your fuel system. Have you checked your fuel filter and pump?

I had a similar issue and it turned out to be a faulty spark plug. You might want to get that checked.

Has your mechanic checked for any vacuum leaks? That could also be a cause for frequent stalling.