[ap3]

Anecdotally: my kid that grew up in the US in a spanish speaking home speaks fluent english. The other one that moved to the US at 4 speaks english with an accent.

No one speaks english at home, same people at home - only difference is the language on the TV. It works.

[andreasvc]

He probably has peers that speak English with him, that has a larger effect than the language spoken at home, or on TV.