Spell all the words!

My six-year-old students must think I’m omniscient. One of them asked me whether I could “spell all the words”. He wasn’t asking about all the words in the wordlist for chapter three, or something like that; he was asking about all the words in the English language. I think I said that I can spell a lot of words but not all of them because English has so many. Imagine believing that a language has a particular number of words and no more!