Questions & Answers about Hún flutti í sveitina í sumar og er mjög ánægð þar.
Icelandic is comfortable mixing tenses like this when it makes sense logically:
- Hún flutti í sveitina í sumar – flutti is simple past: she moved (at some point in the past, this summer).
- (hún) er mjög ánægð þar – er is present: she is (now) very happy there.
So the structure is:
- Past event: the move already happened.
- Present state: as a result, she is now happy there.
If you said var mjög ánægð þar, it would suggest she used to be happy there at that past time (this summer), but you say nothing about how she feels now. The original sentence specifically suggests an ongoing present happiness.
Í sumar almost always means this summer (the summer of the current year or the most recent summer, depending on context).
- í sumar – usually this summer
- í sumarinu – in the summer (more general, with the definite article)
- á sumrin – in (the) summers / every summer (habitual)
So your sentence is best understood as:
- Hún flutti í sveitina í sumar – She moved to the countryside this summer.