If you want to teach your kids a foreign language, the last thing you want to do is try to get them to sit down with a grammar and a dictionary (especially if they are younger). As adults we develop different strategies for learning and assimilating knowledge, but most of them aren't suitable for learning to speak a foreign language. If you want your kids to speak a foreign language, the best way to start is to get them into an environment where they hear that language spoken on a regular basis. Their natural language learning ability is geared to learning by listening and responding. If your kids are the right age, try getting children's books in that language. There are also lots of fun illustrated books that teach kids vocabulary words in different languages. Try to avoid an approach that requires them to grapple with grammatical concepts and rote memorization as much as possible. Later you can add that sort of thing, but your main goal is to get them started by helping them develop a feel for the language and become comfortable with hearing it, even if their understanding is spotty at first.