When is the best time to immigrate?

For children, it will take 6-7 years for many primary and middle school students to use English as their mother tongue. If a child can live in an English environment before 12 years old, but not later than 14 years old, then English pronunciation can be as authentic as mother tongue. If 12 years old goes abroad to settle down, the child's English pronunciation is likely to have an accent in the future and will never change. It's like when we were in China, Putonghua was popularized by the whole people, but not many people spoke it up to standard. Many people have never changed their local accents in their lives, and various Putonghua of Trump and Hampton was born. Non-standard pronunciation will inevitably increase communication barriers and will be limited in finding a job in the future. So if it's for future generations, the sooner you immigrate, the better.