"Why is he so serious?"
Translation:Dlaczego on jest taki poważny?
Okay... I don't get it. Could someone someone explain how 'On jedt taki poważny' s the same as 'tak poważny'? I always thought 'taki' only meant 'that kind of'. As an example, ' On jest taki po prostu.' in others words, 'He's just lke that'.
"Tak" can be compared to English "so" (adverb). "Taki" is similar to "such" Is there much difference between them in English? In Polish not so much.
Well, you can't say "He is such serious" in English. You can say "He is such a serious person", though... My first guess is that "so" is for adjectives (like "serious") and "such" is for noun phrases (like "a serious person").
"serio" is an adverb, and on top of that it's a colloquial one.
"On tak (na) serio?" would work as "Is he for real?", "Is he serious?" in a colloquial way. Like when you hear a guy saying that stones have feelings and you wonder if he is joking or speaking seriously.
For sure you cannot substitute "tak" + adverb with "taki", that wouldn't make sense.
For adjectives... I think you can always change "taki" to "tak", although there may be something that I can't think of right now.