allophones

The dictionary tells you pronunciation for words like "sky" and "star" are [skaj] and [star] but in actuality the "t" isn't pronounced as [t]. Why is it so and why doesn't the dictionary say this? If the dictionary doesn't tell you this, then is your choice only to listen to how native speakers say them and to try to imitate them?

I forgot to say that the "k" isn't exactly pronounced as [k], either.

I think the answer is one of phonology. Sounds like "k" and "t" are generally aspirated in English, but they're not aspirated when preceded by an "s" (unless the "s" belongs to the previous syllable, which the dictionary does indicate). Since the rule is regular, and I expect that it would come naturally enough with time, there is little need to distinguish these sounds in dictionaries.

- Kef

sky is not pronounced [skaj] but [skaI].

[skaj] is also right. It's diphthong.

What about [skahy]? (Think it was deleted before?)

Some people say [ska:], don't they?