The regular verb endings in English are the letter ‘s’ for present tense (she walks) and the letters ‘ed’ for past tense (she walked). Did you know that both of these endings each have three different pronunciations? Try saying, “She walks.” You will hear a slight /s/ hissing sound on the -s ending. Now try saying, “She walked.” You will hear the -ed ending as /t/, a quick flick of the tongue followed by a release of air. Both these sounds are described as ‘voiceless’ because they primarily use air (and not your throat) to create them.
In contrast, there are the ‘voiced’ verb endings, for example, “He plays.” The -s ending is a /z/ sound that you can actually feel in your throat. Similarly, the -ed ending for “He played.” is voiced as /d/ so that you hear the small sound “duh” rather than just air.
There are simple rules for pronouncing these two types of endings which are used in all regular English verbs. I will be happy to teach you them!