You probably already know that all English words that are regular end in ed when used in the past simple, but did you know that ed has three different pronunciations in English?
We have the /id/ sound, the /t/ sound and the /d/ sound but we only have one spelling. One way to learn this and improve your pronunciation is to make a record of the words you know according to their sound. This will help your brain to monitor the difference.
Click on the link to find a worksheet to help you record words by their pronunciation.