If the "ed" is preceded by a (a)   such as K, it should be pronounced as a voiceless T. Examples: parked, barked, marked

If the "ed" is preceded by a (a)   sound such as B or V, it should be pronounced as a voiced D. Examples: robbed, thrived, shoved

These are the (a)   B, D, G, J, L, M, N, Ng, R, Sz, Th (as in the word "then"), V, W, Y, and Z.

These are the (a)   Ch, F, K, P, S, Sh, T, and Th (as in "thing").