One of my favourite things to do in online forums such as Stack Overflow, where there are many non-native English speakers, is to determine where a person is from based on which grammatical errors they make. It’s more subtle than accent or other cues, but it is remarkably consistent.
I followed Andrew Ng's Machine Learning course on Coursera. The course itself was great, but halfway through I realized he had to be from Malaysia or Singapore, because he started talking about "alphabets" instead of "letters".
As a former (non-native) resident of Singapore, that's one of those features of the local lingo that makes me shudder every time I see it, but it's probably already crossed the line from "mistake" to "accepted local evolution". It certainly is well entrenched, as I've seen it in bank letters about choosing good passwords, and it's in this university policy as well:
Quite a few other telltale Singlish features in there as well, eg. the use of "staff" to refer to a single employee and using "credential" instead of "credentials". Both of these are rooted in how Chinese and Malay lack a grammatical plural.
Yeah, besides word choice (“I have a doubt” = “I have a question” in Indian English) you also have more interesting things like discourse deixis—“consider that code: …” instead of “consider this code: …”—or how uncertainty is expressed—“some” instead of “a” for example shows up in Daft Punk’s “Something About Us”.
Interesting! "I have a doubt" is also a common mistake for us Spanish speakers. This is because for us "tengo una duda" is an acceptable way of saying "I have a question".
My old boss was once setting up a patient when he asked where she was from, "as I have a good ear for accents, but I can't tell if you're from Rhodesia or South Africa". Her response was "It is good - halfway through my childhood, we moved from Rhodesia to South Africa"...
I find it really easy to tell people who are native german speakers, based on learning german for years, and having had grammar drilled into me. I dont think there's been a time when I've picked up on it, and been wrong