Could an Alien learn english from books?

That's a fair point, but if they can get a hold of one of our books we have to assume they are very technology advanced.

I doubt they would immediately think "Oh what's this a meaningless rectangular mass that can tell us nothing about the beings who made it?"

I make absolutely no assumption that possible aliens would have any senses as we recognize/identify them.

The closest thing I can think of to a sense that I might, maybe, expect is some ability to identify vibration (or something similar).