왜 항상 지각하는 거야?
In this sentence 거야 doesn't mean future tense... can you explain me this?
It might help you to look at the sentence ending 거 (야, 예요, ㅂ 니다/까) as a contracted form of 것이야, 것이에요, 것입니다, 것입니까 etc. Following that, 거야 means like (this thing) therefore the pattern "~~는 거 (야, 예요, ㅂ 니다/까)" functions similar to ~~ing it-is/ is-it?
compare to "is it" this sentence:
Why is it (you) are always (being/coming/arriving) late?
Why always late coming is it?
Now concerning tense (past, present,future) with regard to this construction (without getting into too much complicated detail) keep in mind that the preceding particles serve the function of indicating tense:
ex: 할 것이다 (will do), 하는 것이다 (doing), ~ㅆ던 것이다 (was/has been done)
