Well I'd pronounce it thresh-hold; the h being not completely gone, it's still there but sort of merged with sh, especially in faster speech.

No, an un aspirated t is the t sound you find in words like 'master' and 'after'. It's like the ordinary (aspirated) t, with the only difference being that you don't pronounce it with an 'h' sound or with a breath as you would with the aspirated

Agree with Philip. The IPA as you wrote it is indeed a /t/ sound. Are you sure that what you heard was a /j/, and not an unaspirated /t/?

Frog? Clock has also that vowel. We have that vowel in Italian too. Why do you say it's weird? I think there is that vowel in American English, for those who distinguish "cot" and "caught". The vowel in frog (and hot and got, too) is indeed a

Can you give examples of words where you think this is not always true? Hi Maple, Were you by any chance thinking about words like newspaper and passport where the /p/ in the second syllable is aspirated? If so, I am inclined to think that the

The first one: It's been a long time since I saw one of those.

The short answer is: No

By the way, how can I say the strong syllable. Its GArage or gaRAge? I'd say both are correct. It is just a matter of British and American English. In BrE the stress is usually on the first syllable while in AmE the second. Hope this helps.