"English as a Second Language" would be my guess, but I've never seen that used as an abbreviation

It's a very common abbreviation for that

It's what they call (called?) the school programs in USA.

We have that in Canada too

Sorry, edited for clarity.

PS: I learned that acronym less than a year ago, so maybe it is not as used as I thought.

It's pretty common, but I guess just for English people (or maybe just in Canada as hinted in another post?)? Either way I'm all for eliminating acronyms in public posts!

It's very common the US as well, but primarily in education circles. I honestly have no idea what percent of the general public would recognize it immediately (hard to know for anything, really).

It's common and wrong. I had to do "ESL" courses at a Canadian secondary school, even though English is my third language, not second.

Ha, technically correct but also a little nitty. "First" and "second" are colloquial used here as "main" and "other." But again, you're not wrong.

Even if we were to admit that "first" meant "main" and "second" meant "other," it would still be wrong, because it is possible for your first language to no longer be your main language, which is the case for me.

Right. Again, it's colloquial. These things happen in languages.

I know, just felt like being nitpicky :)

All good :D

Is this thread just toying with the metrics?

"Subsequent Language"? "Successor Language"? "Secondary Language"?

Feel like there is an "S" word that works

English for Speakers of other Languages