My oldest was 3 when we moved to the US my youngest was born there. Every year they spend 6-8 weeks in Denmark with their grandparents and at home we speak Dani

My oldest was 3 when we moved to the US my youngest was born there. Every year they spend 6-8 weeks in Denmark with their grandparents and at home we speak Danish and only occasionally do we speak english with them. They both have less vocabulary but the oldest can read both Danish and English. We never taught him to read danish but believe that spending time in Denmark for that amount of time still exposes them to enough Danish to internalize some of the language constructs and general orientation of language. It's been quite interesting to follow.