I was taught that the verb comes at the end of the sentences: Pater severus est

This doesn't make sense. The words can be in any order. If Duolingo is going to enforce an order then at least have the verb at the end of the sentence, which is considered better form. I got marked wrong for this one for putting the verb at the end of the sentence, but also marked wrong earlier for putting it in the middle. Especially frustrating on what is supposed to be an assessment of skill