English is a very common second language, world wide.
Indeed, teaching ESL is a popular way for university graduates to see the world at a low cost. My nephew taught ESL for some years in Japan, came back to Canada with a Japanese fiancee who couldn't take the culture shock. But he still teaches some 20 years later, at a private college in Winnipeg.
Scammers often use really bad English, not out of ignorance, but because this is a good way to winnow out the more intelligent and educated recipients, and find the ignorant or quasi-literate marks who will fall for their scams.
