Report it as a bug to Duolingo here (https://support.duolingo.com/hc/en-us/articles/204728264-How-do-I-report-a-bug-) so they can hopefully fix this :-)
You know how Spanish speakers add an "es" sound to the beginning of English starting with an S followed by another consonant? "You are estupid." Arabs do that even more often. We don't have consonant clusters at the beginning of the syllable in Arabic at all, so we always add a vowel at the beginning of words when there are two consonants in a row. It's usually "i," but becomes "u" in certain situations where the vowel following the consonant cluster is also an "u."
MSA does allow a syllable to end in up to two consequetive consonants. And even when a word ends in more than two consonants, it wouldn't make sense to put the vowel at the very end, as that wouldn't really be breaking the cluster apart, now would it? An Egyptian pronouncing "pants" would say [ˈbæn.tɘ̆s], not ['bæn.tsɐː]. The long -aa at the end of the word "uskutlandaa" has nothing to do with phonotactics; it's there for the same reason that words ending in "-land" in English end in "landia" in Spanish, Portuguese, and Italian, and "-lande" in French.
I am a bit confused about the role of Hamza ء and Alif ا in the arabic word for Scotland.
1) If Alif is only to prevent a consonant cluster at the beginning of the word, there shouldn't be Hamza and من should be vocalized as follows: مِنَ.
2) If Hamza occurs in the word, why is it not أُسْكُتْلَنْدا?
May someone please clarify?