How do you pronounce "ed" in past tense?

How do you pronounce the "ed" sound in past tense? I'm not sure but when I watch TV, it looks like sometimes people pronounce it as "d" sound but sometimes as "t" sound. Are there any rules regarding how to pronounce it? Please explain in details. I want to learn how to speak... show more How do you pronounce the "ed" sound in past tense? I'm not sure but when I watch TV, it looks like sometimes people pronounce it as "d" sound but sometimes as "t" sound. Are there any rules regarding how to pronounce it? Please explain in details. I want to learn how to speak proper English. Thanks.

PS. English is my second language.
Update: From Chancelikely:

"If the sound before the 'ed' is a vowel, it seems to be pronounced [d]. "

Can you or anyone please give examples? Thanks.
7 answers 7