Is this correct grammatically?
Los muchachos fueron a las montañas cada invierno.
2 Answers
If they were at the mountains every winter, then it would make more sense to use the imperfect, as it is a repeated action of the past.
Los muchachos iban a las montañas cada invierno.
It says the boys were at the mountains each winter. "If you hilight one word at a time it will translate it for you." Or just use the translator