A correspondent in the United States (Mark Spahn) writes:|
SUPPOSED TO, USED TO, HAVE (HAS) TO
I checked three learners' dictionaries: Longman Advanced American, Oxford Advanced Learner's, and Macmillan English.
None notes the voiceless version of "supposed." All three give "used
to" as a headword and note the unvoiced "d." Longman and Oxford note
the voiceless version of "have"; Macmillan omits it.
Note that these three phrases have different meaning depending on
whether the relevant consonant is pronounced voiced or unvoiced. "I am
/suppozd/ to be in charge" means that people suppose that I am in
charge, while "I am /suppost/ to be in charge" means something
different: that I should be in charge.
Toothpicks /yoost/ to be /yoozd/ for picking teeth, but nowadays they are /yoozd/ more often for building miniature models.
"What do you /haf/ to do?" means something different from "What do you /hav/ to do?"
In the third-person singular form, "whatever he /has/ to do" means something different from "whatever he /haz/ to do".
The dictionaries I have looked at note the differences in meanings, but not the corresponding differences in pronunciation.
I then checked a half-dozen dictionaries for native English speakers. Only one, Merriam-Webster's Collegiate (93), gives the voiceless pronunciations of all three words.
(July 13, 2003)