"it was a commonplace of medieval schoolroom practice that legere (meaning 'reading' in the sense of proncouncing the text correctly) preceded intellegere (meaning 'understanding' the text through grammar and vocabulary). Children might learn 'reading' at home from their parents using a primer, but they could only achieve 'understanding' in a grammar school– and these schools were restricted to boys. Because women got no schooling in grammar (which meant Latin), they missed out on learning to write as well, since writing was taught by copying out the alphabet and Latin vocabulary. Even though signatures (instead of seals) were increasingly being required from women as men to authenticate legal documents, the numbers of women who could write in 1500 may have been as low as 1 percent of the population.
"Inability to write contrasts with the large numbers who might have been able to read, at least in the restricted medieval sense of legere. Derek Brewer estimates that in England 'probably more than half the population could read, though not necessarily also write, by 1500.' . . . This estimate depends on the number who might have been instructed–in the home rather than at school–in the basics of the reading primer. Certainly by 1500, and probably as early as 1200, writing had become familiar to the whole medieval population: as noted above, 'everyone knew someone who could read.". . . Book-learning had been integrated into the life of the male clerical elite of monks and priests by the beginning of our period in 1100. The achievement of the years 1100 to 1500 was to extend the book-learning from monasteries and churches into the domestic sphere of the family. The reading primer, which reinforced the link between religion and learning as strongly as the clergy did, had the potential to make everyone a literate and a book-owner. Shortly after 1500, booksellers' catalogues were selling primers, described as 'abcs's', for a penny each. These were printed booklets, but their form was the same as it had been for centuries" (Clanchy, "Parchment and Paper: Manuscript Culture 1100-1500," Eliot & Rose (eds) A Companion to the History of the Book  205).