"Teacher, why is this word wrong?"
Translation:Opettaja, miksi tämä sana on väärin?
As MikaLaari says, this is the only normal word order, but in poetry other orders are possible.
Why is this the normal word order? The basic indicative sentence, a statement, is Tämä sana on väärin or "A is B". When you form a question with an interrogative word, a question word, i.e. with anything else than the ending -ko/kö, you retain that word order. Note, that in English you switch to reverse word order.
- Miksi tämä sana on väärin? : Why is this word wrong?
- Missä tämä sana on väärin? : Where is this word wrong?
- Miten tämä sana on väärin? : How/In what way is this word wrong?
Opettaja is a vocative, an expression of direct address, to get hänen: he/she/their attention. It reveals, that this is a spoken situation, where practically nobody would use a poetic word order. Therefore "If starting with opettaja, not really".
Technically it is correct, however nobody speaks that way nowadays.
When you form a question with an interrogative, question, word like miksi : why, you just simply put it into the beginning of a statement.
In the proto-Uralic languages a statement had the verb at the end, i.e. with contemporary words
- Tämä sana väärin on.
so a question was
- Miksi tämä sana väärin on?
However because of influence of Indo-European languages, mostly Swedish, the word order changed in the contemporary Finnish. (English is also an IE-language.)
- Tämä sana väärin on → Tämä sana on väärin.
i.e. the position of the predicative, main verb, was altered. I don't know when this shift occurred, but sometime after the Swedes came for 800 years ago and before the 1900 century..
Note, that the way how questions are formed, did not change, so
- Miksi tämä sana on väärin?
Actually the reverse word order used at least in the germanic languages (incl. English), a subgroup of the IE-languages,
- Miksi on tämä sana väärin?
sounds really awkward.