"Is the band Icelandic?"
Translation:Onko bändi islantilainen?
A question begins with a question word, in this case onko which is a combination of on and the interrogative suffix -ko. If on was at the end, then another question word would have to start the sentence, which in this question wouldn't really work without altering it quite a bit.
I don't know which previous lesson specifically you could be referring to because I would be extremely surprised if that kind of word order would be used for an interrogative clause. Firstly, the word order there is subject-predicative-verb, and it's very unusual to not have the verb between a subject and its predicative. Secondly, there is no question word there, so it's not a question. A question word would be an interrogative adverb (e.g. "missä"), an interrogative pronoun (e.g. "kuka") or a verb with the interrogative suffix -ko/-kö. There are two ways of forming interrogative clauses:
- When is no interrogative adverb/pronoun in the question, the word order is generally the same as it would be in English and the verb gets an interrogative suffix.
- When there is an interrogative adverb/pronoun in the question, the word order differs from English because of the fact that the subject and the verb do not swap places, so the usual SVO order (subject-verb-object) is followed. For example, "Missä hän on?" would be "Where (s)he is?" when translated word-for-word into English.