I'm opening up this discussion again because I think it's very important. The new incubator will be up and running soon and we will have the opportunity to expand on the content available in languages that already exist on the site. I wanted to make a list of vocabulary areas that I think should be added. You can comment with any you think of. You can never have too many words!
Vocab topics; Around the House, At School/Work, Cooking Terms, Culture, Furniture, Holidays, Media, Special Events, Technology
The English Profiles by Cambridge University Press have lists of vocabulary for various language functions, general notions and specific notions: http://www.coe.int/t/dg4/linguistic/dnr_en.asp (scroll down to English)
I think the "Lexical exponents of specific notions" sections in those documents may be what you are after.
Normally I would have put in a warning for "boring language teaching stuff" before introducing these documents to others, but I guess I don't need that here. ;-)
I'm sure over time the vocab quantity per language will increase but it'll probably based on the most common words that need to be translated (i.e. words that are most commonly used in online articles).
I don't know if there are lessons for it (since I haven't completed the entire tree), but more colloquial sayings/expressions/phrases would come in handy to learn - both for us the individuals and the recipients of the service that we (the translators) provide.
Yeah! They could even take it a step further and have like at the restaurant or grocery store and you could learn not only even more foods, but also useful things to say like "I would like to order.." And "how much does this cost?". And they could do like a gardening or at the farm one and you can learn stuff like "shovel" and "seeds" and "gardening hose". This is making me too excited I love learning new words!^^