I have had English in school, but I have mostly learned English by reading books. I never did homework, never learned grammar or vocabulary, but rather, similar to a native speaker, I took up the words, their meaning, and how they were used from the texts that I read.
This approach worked for me, because I was extremely motivated to read the books I read. It didn't hold me off that I had to look up words in a dictionary in almost every paragraph. But not everyone learning English is as motivated as I was to read books that were written for native speakers and require much effort from beginning or intermediate learners.
Not all books written for native speakers have the same complex grammar and use the whole range of English words. Even for native speaking adults, there are books (like popular fiction) that use a somewhat simpler language, and books for children and middle grade readers often use simplified language as well.
Now the problem is that native speaking pre-schoolers already have a vocabulary that is much larger than that of adolescent learners of English, and adolescents might not be that interested in reading childrens' books. So what I'm wondering is how I could identify books written for native speakers that have a limited vocabulary that doesn't overwhelm English learners of a certain level.
Is there some list or database that orders books by the extent of their vocabulary? Or is there another way to find books that don't require a demotivating perusal of a dictionary?
I know that there are books specifically written for language learners, but most of these only cover the first two or three years of language learning, the selection is quite small, and most of the books aren't all that exciting to read.