Fabio Capello, manager of the England football team,has justified his poor command of English by saying that he only needs a hundred words of English to get his message across to the players (see this article).
So, is that true? Can you get your message across in a hundred words?
Most people know 50 or 60,000 words in their native language, according to Professor David Crystal. But that doesn't mean you use all those words. I know the words euphonium, off-side and avast, but I never use them in ordinary conversation, as I'm not musical, sporty or nautical. Generally speaking most of us recycle the same (relatively) few words over and over in our conversation. When I say 'relatively few' I'd hazard a guess (and it is only a guess) that most of us use on a regular basis fewer than 10% of the words we know, and this amounts to a tiny proportion, probably less than 1%, of the total number of words in the Oxford English Dictionary.
Some sources claim that about a hundred common words (the, and, for, of etc) make up about 50% of written texts. If you knew a thousand words (or word families, which means that you'd count eat, eats, ate, eating and eaten as just one word) you'd probably understand about 70% of the words in a text, and if you knew 2,000 you'd probably understand about 80% of them. The trouble with that statistic is that understanding words like the, because, in, by, with, from etc is not a great help when it comes to understanding the overall meaning of a piece of English.
Incidentally, in the Sun article linked to above, there are about 750 words in total. Stripping out the names, and then any duplicate words I calculate that there are about 280 different words used in the text. As mentioned above, there are lots of instances of the, of, he, when etc, and, given that this is a text about football, there were several instances of the words player, game, team, squad, good, win etc. There were also several instances of 'really', which, apparently, is one of Capello's favourites.
Don't let all this talk of hundreds, or thousands, of words put you off learning a foreign language. You can, indeed, do a huge amount with a hundred words. I expect that when my children were toddlers, I used a very limited vocabulary to communicate with them, yet we had fun and they learnt. Foreign language teachers can convey a lot of information and instructions with a very restricted range of vocabulary. When I used to teach Russian I promised my students that learning just seven words would vastly increase their enjoyment of a holiday in Russia and would really impress the Russians. The seven words were: здравствуйте (hello), до свидания (goodbye; ok I know the Russian is, strictly speaking, two words), пожалуйста (please), спасибо (thank you), да (yes), нет (no) and можно (may I? or Is it possible/allowed? - and this little word, accompanied by a gesture will enable you to ask if you can smoke, sit here, open the window etc).
If the hundred words Capello knew were knitting or culinary terms, then they would not be much good to him in talking to his squad. However, if each word is relevant, well-chosen and motivating, then I think that he probably can get his message across. Presumably there are only a limited number of things that one needs to say to footballers about to go into a match and presumably they already know what they need to do.