Even though, your parents came here to be American, they were grateful to be here and were going to do their best to make sure you and your siblings took advantage of the opportunities.
My grandfather came from Italy at 15, taught himself english, he married my grandmother who was born here but was also Italian. They could speak to eachother but, Italian was not spoken to the kids. English only.
"English only"
And there lies much of the problem.
Same with my mother-in-law. She is Japanese, married a US Army guy, had kids, etc. etc. but never taught/spoke to their kids (my husband, his brother, & two sisters) in Japanese.
:o(
('Cause he would have made out like a bandit in the 1980s & 90s if he spoke fluent Japanese)