As my cousin Howard reminded me, my parents also learned English.  They came to England in 1939 and the records note that they knew no English.  But by the time I came around, they were pretty fluent, and even figured out the different between British English and American English.

And before that, my grandmother learned languages.  One of my first books had this poem:

A Lithuanian Legacy

The soldiers would come
into my grandmother’s yard
pull the head off a chicken
and thrust it into her hand

Cook it    woman

The Russian soldier the German
then
the Russian again