You are missing my point. He is FOUR. Shouldn't he learn English first?

Instead of teaching him two new Spanish words per day, I would rather 'they'
teach ONE new English word!!

He is learning more english than you are aware of. As you say there is
nothing but good about being bilingual.

All this reminds me of a friend who teaches kindergarten. 20 all day
long in her class. The usual mix is at least 10 who speak only one
language and it is not english or spanish. One year there were 14 who
spoke only one language and it was not english or spanish. After 6
weeks with lots of recess time they all spoke english as well as any
kindergartener. And se impressed the parents to keep up the other
languages.

Bob AZ