he literally could not speak one word of English.
colour me cynical, but I've seen some people who "can't speak a word of English" miraculously acquire it, when circumstances demand.
My Dad (immigrant) picked up a lot of Indian words when he worked for an employer (the English staff refused to socialise with the Indians and foreigners for tea/lunch, so it was necessity).
When he ran his own business, and dealt with Indian customers, they would sometimes bring an elder (who had the money) and have intense discussions in their native tongue. The look of shock on their faces when my Dad commented was priceless. After that, they quickly all spoke English.
(To be fair, my Dad has on occasion played the "can't speak English card" himself).
Because my name follows my fathers, when I was younger, I was complimented on "how well I had learned English". "Yes" I'd say "not bad for someone born in London.". I also got told to fuck off home a lot. I'm starting to feel nostalgic for the 70s 