about pronunciation

hi teacher.. i wrote this 'cause i'm wondering how could I make a pronunciation when i'm saying as " (any verb)ed + to " form sounded like native speaker. Let me get some advices to help.

[Tdol]

It depends on the way the verb is pronounced. If it isn't pronounced as a syllable, the the 'd' often disappears, so 'happened to' ofte becomes 'happento'. If it is pronounced as a syllable, then the sound blend a bit and the 'd' is pronounced, but less than the 't'.