Who decides English language rules?
English does not have an equivalent to the Académie française . There are no 'official' rules, only accepted conventions. Some of these conventions are effectively rules because they are inherent to the language's grammatical structure. No native speaker would naturally put the noun before the adjective in the sentence I bought a red car . (I a red car bought) But they might break another 'rule' by starting a sentence with a conjunction, as I just have. In this case, the rule/convention comes from another language: Latin. Is there an official English language rule book?