Simple Past Tense - "ed" as /t/ / Simple Past Tense - "ed" as /t/
If the verb ends in an unvoiced consonant (p, k, f, gh, s, sh, ch, ss, c, x), then the –ed ending sounds like a /t/.
You can use your fingers to touch your throat and say the sound. If the throat doesn't vibrate, it is an unvoiced sound.
For Side by Side 1, unit 15. No copyright infringement intended.