Apparently, many non-native English speakers write code with comments and even identifiers in their native language. The problem with this is that programmers who do not speak that language will have a hard time understanding what is going on here, especially after the writers of the foreign language code post it in to an Internet forum in order to get help with it.
Consider what Eric Raymond wrote in his "How to Become a Hacker" document (where hacker is a software enthusiast and not a computer intruder):
4. If you don't have functional English, learn it.
As an American and native English-speaker myself, I have previously been reluctant to suggest this, lest it be taken as a sort of cultural imperialism. But several native speakers of other languages have urged me to point out that English is the working language of the hacker culture and the Internet, and that you will need to know it to function in the hacker community.
Back around 1991 I learned that many hackers who have English as a second language use it in technical discussions even when they share a birth tongue; it was reported to me at the time that English has a richer technical vocabulary than any other language and is therefore simply a better tool for the job. For similar reasons, translations of technical books written in English are often unsatisfactory (when they get done at all).
Linus Torvalds, a Finn, comments his code in English (it apparently never occurred to him to do otherwise). His fluency in English has been an important factor in his ability to recruit a worldwide community of developers for Linux. It's an example worth following.
Being a native English-speaker does not guarantee that you have language skills good enough to function as a hacker. If your writing is semi-literate, ungrammatical, and riddled with misspellings, many hackers (including myself) will tend to ignore you. While sloppy writing does not invariably mean sloppy thinking, we've generally found the correlation to be strong — and we have no use for sloppy thinkers. If you can't yet write competently, learn to.
So if you're posting code for public scrutiny, make sure it is written with English identifiers and comments.