Many years ago I read somewhere that Shakespeare had a vocabulary of over 45,000 words - but has anyone come across research which tells us what size of vocabulary we need to speak: a) our own mother tongue b) get by in foreign language which we are learning and if there are such studies, do they distinguish between words which we understand when we read or hear them, but which we would rarely if ever use, and the more limited vocabulary which we fluently use when we are speaking or writing. Building up a vocabulary and learning words is hard work, a real memory slog, so forgetting about the niceties of grammar and syntax, if you were to build up a vocabulary say of 5,000 words, would you be able to understand and get by in a foreign langage. That also begs the question of word recognition of the written word, vis à vis the spoken word. And in my maternal language, (English) would a Sun reader for example have a vocabulary of say 5,000 words, and a Times or Telegraph reader a vocabulary of 15,000 to 20,000 words? And what of the last Pope who would give his Easter message in 70 languages, and go into a meeting with 5 or 6 prelates from different parts of the world, and converse with them in their own language. Was his brain controlling say a total vocabulary of 200,000 words? In the three months or so I have been following this language forum, it is apparent that the moderators and other contributors have a mastery of French & English - what size of vocabulary have they at their command?