I have read La sombra del viento four times in Spanish. The first time was a slog. The fourth time was a small marvel. The slow accumulation of what changed between those readings, more than any course I have taken, taught me what reading in a foreign language is actually for.

The first reading was the standard intermediate experience: a dictionary at my elbow, a notebook for vocabulary, an average pace of about ten pages an hour, and a creeping awareness that I was understanding the plot and missing the book. Whole passages went by as collections of glossed words, none of which I retained. The notebook eventually swelled to four hundred items, of which I might have remembered thirty. I finished the book and felt I had been put through a chore.

The second reading I gave myself a year later, by which time my Spanish was a little stronger and my patience with the dictionary much thinner. I looked words up only when I had no idea what was happening. Most of the time I leaned on context, on cognates, on the structure of the sentence — and to my surprise this worked, not perfectly but well enough that the prose started to behave like prose rather than a code. The character of Daniel began to feel like a person rather than a scaffolding of pronouns. I made it through faster, with less effort, and almost no notes. What I had treated as a vocabulary-building exercise the first time started to feel like reading.

I read it a third time because I had wanted to teach myself to enjoy fiction in Spanish, and I did. By this point individual words rarely tripped me. Sentences came in waves rather than as discrete units to parse. The descriptions of Barcelona, the architecture and the alleys, registered as images rather than diagrams. I noticed that the prose had a particular rhythm, that Zafón uses certain conjunctions in certain places, that his sentences were often longer than I had assumed. I started to notice the writing rather than just the story, and the noticing happened almost without effort, because the language no longer demanded all my attention.

I read it a fourth time, and this is the one I think about. By the fourth pass the book had become almost transparent, and what I started to see was not the language but the construction. The way the central mystery is set up in the first thirty pages and then deferred for two hundred. The way minor characters are introduced casually, as if in passing, and then become central. The way certain phrases recur as motifs without announcing themselves. I had read the book three times in Spanish and once in English, and only the fourth Spanish reading made the structure visible. It was, in retrospect, the only reading I would call literary in any honest sense.

I am told this is what learners are supposed to do — read the same text repeatedly, build familiarity, let the language become invisible — and yet most of us refuse. The instinct is always to move on. We have a list. We finish one book and reach for the next, because finishing is the metric we trust. We assume rereading is for children who don’t know better. There is even a kind of mild shame in admitting that a book you finished six months ago was not, really, finished in any meaningful sense.

If I could go back I would have read La sombra del viento four times before moving on to any other novel. I would have done it because the second reading was easier than the first, the third easier than the second, and each pass added something the previous pass could not. By the fourth reading I was no longer a learner working through a book. I was a reader. And it had cost me about as much time as four different novels would have, with results not even comparable.

The most useful thing the practice of rereading does is uncouple progress from novelty. You stop measuring how far you have come by how many new texts you have processed and start measuring it by how much of what you have already encountered you can actually use. This is closer to how readers in their first language work — most of us reread the books that matter to us, sometimes obsessively, and nobody finds this strange. In a foreign language it suddenly seems indulgent, as if rereading were a luxury for people who weren’t trying to improve. In fact it is one of the few practices that compounds.

I have since read other novels four times — Le Petit Prince in French, a Chekhov collection in Russian I am still working on. Each time the curve is the same. The first read is work. The second is reading with friction. The third is reading. The fourth is reading as a writer would read. I cannot recommend the practice strongly enough. The shame, if there is any, is in having spent so many years assuming that to finish a book once was enough.