How do you pronounce it would, it was, etc ( in American English) ? That is, how do you pronounce the "T" when it precedes a semi-vowel like w? Is it a stop T, or even no T at all when pronounced fast ? When followed by a vowel, it's a "flap T" ( ex: " it is") , and when followed by a consonant, it's a full T ( ex: "it looks"), as far as I can see, but this I can't nail down.
In many dialects, /t/ before a consonant (including w) is pronounced [ʔt] or even [ʔ], that is, glottalized or preglottalized.
(Edit to clarify: that is, /t/ before a consonant, except for initial /t/ which is not glottalized.)