Wonder if "...younger than I", was accepted? Didn't want to try it bec. I didn't want to lose a heart (testing out). Both forms should be accepted. http://www.onlinegrammar.com.au/than-i-versus-than-me/
I was not going to use the "Report function" since my answer was correct. I was just wondering if the other form would be accepted by Duo, that's all. I did not want to use the other form because I was Testing Out and did not want to lose a heart. So, I'm (still) asking people who tried "...younger than I", if it was accepted.
I tried the "... than I" construction, but not on purpose, it was an honest attempt, an "accident", otherwise I should've thought along the same lines as you: That it probably won't be accepted anyway and, sure enough, that's what happened. ;-) It's the only reason I commented at all, although in my case it wasn't this sentence but an earlier one. As for the rating thing ("downvoted"): not that important.
(Ja) lubię go mniej niż (lubię) ciebie - I like him less than I like you
(ja) lubię go mniej niż ty (lubisz)- I like him less than you like him
lubię go mniej od ciebie - I'm not sure it's even possible sentence.
Adjective+ niż + nominative or adjective +od+ genitive
adverb, comparing subjects
adverb, comparing objects
adverb+niż+case detemined by verb
but yes "od" always governs genitive and "niż" governs nominative after adjective and case of compared subject/object after adverb.
Idę z człowiekiem (instrumental) wyższym od żyrafy (genitive). I' m walking with a man taller than a giraffe.
Idę z człowiekiem (instrumental) wyższym niż żyrafa (nominative).
I agree with Dorothy. Strictly speaking, "younger than I" is correct and "younger than me" is colloquial. "My sister is younger than I" = "My sister is younger than I am young". Here, you are comparing age with age, which is logical. Saying "My sister is younger than me" is comparing "age" with a "person" which is illogical. It's a classic case of comparing apples and oranges. It may be grammatically correct, as you say, but it is illogical!
Is "Moja siostra jest młodsza niż ja" idiomatically correct in Polish? If so, it would be equivalent to the English expression "my sister is younger than I".