I see this a lot, but it seems hard to verify. Has a scammer actually ever come out and say they deliberately use poor grammar? Would be interesting to compare scam emails/messages from scammers based in the US/UK/Australia with those in India or Nigeria, and see if the pattern holds up for both.
Easy. As you say all you need to do is to compare and as I occasionally have a glimpse of the spam for some non-English language with a non-Latin script - it's the same.
