Are there 20,000 English words in the average adult's vocabulary?
English is not my native language, but I use it on a daily basis. I started reading English literature about two years ago. Mostly I read science fiction and fantasy, but also read other books. Once in a while (several times per chapter) I come across words I need to check in a dictionary. That's all good, I keep learning more. But what I'm concerned with is that I bought a dictionary of 55000 English words, and by my experience I encounter words about once per chapter that are not in this dictionary. And that doesn't count slang or words with mixed endings. Just the words in their basic forms as nouns or adjectives or verbs and so forth.
What I want to know is whether native English speakers have vocabularies of more than 55000 words or do they struggle as I do? I don't think they have such problems, because when I read books written in my native language, I don't.