english

I only know how to write English, but if I knew writing in multiple languages I would write the comment in both languages

No, It will look so wierd.

Using English is the only way that all my colleagues are able to read it, but if it’s just meant for you, or only for Spanish speaking people, I’d say why not.

German here.

I am not writing anything in my code in German. All of my code, my variables, my default texts, my comments, my documentation, my UI strings, etc. are always and explicitly in English.

The only German I use, is when I provide translations for UI or documentation.

My language is rtl, so… shit no!

depends on what everyone else on the project is doing

Always English. I live in a country where developers are hard to find. Chances are that I will get colleagues who do not speak my native language (yet).

…why is this nsfw exactly?

I don’t write a lot of codes, but when I do, it is usually a mixture of broken English and my native language.

This actually depends on the kind of project. In larger and longterm projects I write my comments in English. In quick jobs like writing a source code generator or data swabbler that I need once or relatively short term, I use German. It does not make much of a difference for me, though, and I have a script that walks over a source tree to find some common German words just in case I had written something in German by accident.

This is expected Canadian source code:

// cache the colour in case we need it later for the neighbour
color = fetchColor();
neighbor.color = color;

When language keywords are all written in American English it’s foolish to try to author your code in a different language. But comments are fair game.

Writing detailed and technical comments in English is easier that saying a simple English sentence in real life for me, lol.

I’m French speaking, but I write all code and comments in English, all the time. The code is basically English keywords and symbols, the mix and match just looks weird, makes it harder to share snippets for help or debugging with non-speakers. Especially in code that will be read by other people after the fact, it also tends to make it less likely that this person will be able to understand it - maybe they’ll hire an offshore team or some guy who just immigrated…

I’m Brazilian. For personal projects and snippets, especially if I’m going to share their code publicly (e.g. GitHub or GitHub Gists), I often use English. However, when it’s a project from a company I’m working for, I use Portuguese, as every company I’ve worked for so far are Brazilian (and my coworkers were Brazilian as well).