This doesn't seem to hold true for native English speakers. The number of old white North Americans on Facebook who haven't figured out punctuation, capitalization, or things like their/there/they're is astounding.
As many as 16% of US adults may be considered functionality illiterate in English. A further 26% have serious difficulty gaining understanding from what they read in English. From a department of education study.
Essentially a third of the country can't read much beyond the cat in the hat, if even that.