If we accept unlimited immigration, can we also expect those immigrants to learn English?

[Neo-Malthusian Misanthrope]

I agree with Fuzzy. It's not unreasonable for a recent arrival to only speak their native tongue while working towards their green card/permanent residency. But achivieving such a thing should require effective knowledge of a De Facto official language - I'm not sure of the legal implications of requiring this in a country where such a thing is not Du Jure, unlike in Canada where official languages are both English and French and immigration status can easily be measured in relation to one or the other. For example, if somebody on the Texas border can function entirely in Spanish, can they be required to learn English for immigration purposes? That's a legal question I'm not qualified to answer.