pronunciaton of regular past verbs

[diana de las casas]

What guidelines-rules, if any, can be applied to know how to pronounce correctly regular past tense verbs? or How does one know whether the verb ending is pronounced -d, -t or -id? Thanks for you help!!

[Casiopea]

Welcome, Diana.

If the word ends in

[1] t or d, the past tense suffix -ed is pronounced [Id].
[2] b, v, w, m, n, l, r, z, y, g, the past tense suffix -ed is pronounced [d].
[3] p, f, s, sh, k, x the past tense suffix -ed is pronounced [t].

Note, [1] share the same place of articluation with -d- of -ed, so an extra vowel, [I], is inserted to ease articulation;[2] are voiced sounds, so the past tense suffix [d] is voiced; [3] are voiceless sounds, so the past tense suffix [t] is voiceless.

The rule: /-ed/ changes pronounciation according to its environment. If it follows a voiced sound, it too is voiced, [d]; if it follows a voiceless sound, it too is voiceless, [t], and if it follows the same sound, then a vowel is inserted to ease pronunication, [Id].

If the word ends in the sound:

[1] t or d, the past tense suffix -ed is pronounced [Id].
[2] b, v, w, m, n, l, r, z, y, g, the past tense suffix -ed is pronounced [d]. And when the word ends in a vowel sound?
[3] p, f, s, sh, k, x the past tense suffix -ed is pronounced [t].