Shouldn't "Year and months" be accepted here? Grammatically it makes sense, and I've long given up on applying logic to Duolingo sentences...
It's the same in indefinite singular and indefinite plural: ett år, två år, flera år. It's året in definite singular, åren in definite plural.
A year should (?) have ett before, but if there is no article then it is years (pl). Am I correct and is it always a rule ?
If you were saying " a year and months", but they're saying "year and months". It could go either way here, but this isn't specifically saying "one/a year"
there are a few exceptions, but singular nouns typically don't stand alone in Swedish. "Year and months" would still be "ett år och månader", I'm fairly certain.
I hear it, but since "och" is usually just /o/ it can be a bit hard to hear it clearly in a phrase.