change of vowel in present and past forms?

Luiz   Mon Feb 15, 2010 7:21 pm GMT
I have a lot of difficulty telling if a person has pronounced a present or past form of certain verbs during rapid speech.

Consider the forms: derive/derived

I know that in the past form I should hear the final d, but sometimes I don't hear it.

I'm trying another approach, so I would like to know if there is a change in the vowel in -rive/-rived, so maybe I can distinguish by appreciating the change in the vowel.
schlechtes vorbild   Mon Feb 15, 2010 8:08 pm GMT
Your observation is keen.

At the end of words like "did" or "load," you will usually hear a clear, voiced "d."

At the end of words like "derived," the "d" is not voiced. It's like an soft, unaspirated "t." Listen:

http://www.dict.cc/?s=derived
schlechtes vorbild   Mon Feb 15, 2010 8:11 pm GMT
*** a soft, unaspirated "t"

not "an soft"