Even if everyone is using English, there will be cultural differences. I used to work at a company which had a lot of indian externals working on their code base. Whenever I had to work on a mainly Indian developed project i had to get used to how they wrote things. Usually things where named a bit different. Not by much, but enough tho throw me off a couple of times before i got used to it.

IMPORTANT: I am not shitting on how they used English, merely pointing out that they used it differently from how i would have expected.