Translation:There is an expensive restaurant on this street.
why would هذا not be accepted as well? Is that alif not something more related to the pronunciation of the word without having to be necessarily written down?
Do you mean the short alif on the (H: هـ)? Was it considered a wrong answer because you didn't type it?
I don't work with Duolingo but this is absolutely a grave mistake. Because we don't write it or type it down in normal text in Arabic. This short alif above is just a pronunciation guide and it is found in Quran a lot because Quran's orthography is special and different from the standard of modern Arabic. So such short stroke is used to note that there is a long vowel not written. Duolingo should accept the answer without it.
On this street there is an expensive restaurant, was not accepted. How come? Sometimes Duolingo wants exact order translation and at other times a specific order. Someone Please explain.