That's the difference between people who read, and those who don't. On the flip side, I don't know how to pronounce some of the words that I know how to spell, so when I read I sub-vocalize them incorrectly. There's no need to separately learn pronunciation in my native Russian - it's phonetic, with very few, minor deviations. Nor is there a need to learn spelling - it is governed by very few simple rules.