Actually, the English language is quite difficult to write: so much so, that it's rarely done correctly. (Trust me, I make my living as an editor, and I have no fear of losing my job.) One of the problems is the mixture of English and American usage (not to mention Australia and other English-speaking countries).
Spelling and pronunciation do change over time and vary by country (color vs. colour, gray vs. grey, ee-ther vs. eye-ther, etc.), but rarely does the spoken language match the written language. Unless you're me, but I tend to annoy people when I correct their grammar