Agree that we need more info on these 3 people and their circumstances.
I will tell you that I interview insurance applicants for a living and I speak with people every day who barely speak English and need an interpreter. They say they are US citizens.
My guess is you must have to learn a rudimentary amount of English in order to become a US citizen. Some people seem to never learn any more.
I've had people tell me are in this country on an expired visa, sometimes expired years ago. Some of them foolishly tell me they are working as a nanny and don't pay any taxes.
I don't pry. These are just basic questions on the questionnaire.
Also, you'd be surprised how many people are not citizens, perhaps they have a green card or other visa, however they are on Social Security Disability Insurance.
This job has been a real eye opener.