Grammar is a set of agreed rules, therefore it is not set in stone. Someone might disagree with the rules, and that leads to a slightly different grammar. And so on and so forth. Effectively, everyone has their 'own' grammar that they use. IMHO (especially not being a native English speaker) this article is rubbish (it's in URL BTW). One needs to know his grammar to write articles, but for a developer position? Don't think so.
