I thought Thing Explainer is a fun experiment and a delightful book, but as an attempt (and it isn&#x27;t a serious attempt) to use only simple and super-commonly-used language, it doesn&#x27;t hit the home base. As I speak English as my second language I&#x27;m acutely aware of this.<p>Thing explainer uses the 1000 most commonly used lemmas, but words have multiple senses, and some of them are commonly used and some are not. From a viewpoint of a language learner, an unfamiliar use of a word might be another word for what it&#x27;s worth. (Of course they might have a clear semantical connection, which helps guessing.)<p>Another thing is that phrasal verbs and set phrases are essentially vocabulary items too – you can&#x27;t decode them using only extralinguistic knowledge (that is, knowledge about the world).<p>Randall Munroe developed a text editor that highlights any words outside his word list to help with writing the book, but I think an editor that could handle word senses and multi-word phrases would be a formidable thing. Of course it needs much more high-level NLP, word sense disambiguation and such. (Possibly impossible to pull that off cleanly with the current level of tech?) I&#x27;d love to see one.