As Zesul's pointed out above, each of the "you" forms comes with a different verb ending. In the given sentence ... किताबें पढ़ते हैं, the हैं indicates plural (or formality), which only goes with आप
"You read the books" will have to be translated as "आप ये/वो किताबें पढ़ते हैं।" (You read these/those books.)
I understand that you can stress the fact that you’re talking about books that were mentioned previously by using ये. But we’ve been taught until now that Hindi does not use articles and that the absence of articles could be translated either by “a” or by “the”. There are many examples to this effect in the previous lessons. Am I missing something?
"You read books." can be translated using any of the three words for "you" and the two genders, giving a total of six possible translations:
तू पढ़ता/पढ़ती है।
तुम पढ़ते/पढ़ती हो।
आप पढ़ते/पढ़ती हैं।
I understand that Hindi differentiates between "read" and "is reading" but they are interchangeable in English. I think "you are reading books" should be considered correct.
That would be - Aap kitaab-en padh rahe hain.
The Hindi sentence that is given implies that the person is a reader in general.