More and more parents are eager to raise their children to be bilingual. They know what an important asset this ability will be for their children—opening doors in higher education, the business world, and many other fields. Research has shown that bilinguals tend to be more creative thinkers than those who speak one language, and one study suggests that their brain functions may stay sharper as they age.

Children are perfectly capable of learning more than one language, and even of learning multiple languages simultaneously. It is also important to note that a child's capacity to learn more than one language simultaneously isn't something children have to grow into—they can begin their exploration of language(s) very early, and often with amazing results. In fact, the earlier they start, the longer and richer their exposure will be to the language or languages, and the deeper the effect will be.

Here's how to get your little linguist to begin learning.

Start now. Two- and 3-year-olds are not only increasing their vocabularies, they're starting to recognize the speech patterns they've been hearing since birth. The earlier you introduce a second language, the easier it will be for your child to pick up its unique sounds.

Create a casual learning environment. The best way for a child to learn to understand a new language is for him to hear people speaking it fluently. If he's exposed to conversations, he'll begin to pick up the sounds and the natural accent. Choose a language that is spoken in your neighborhood, on a television show your child can watch regularly, or one that is offered in classes or playgroups in your area.

Teach a word at a time. You can introduce bilingual basics by pointing out to your child that objects can have two names -- one in each language. As your child learns new words, tell him what they're called in a second language too.

Have reasonable expectations. Of course, a child won't learn to speak another language fluently from hearing words, watching videos, or singing songs. But simply being exposed to a language will help her understand phrases when she hears them. So even though you probably won't be having a French conversation with your child very soon, if you say "bonne nuit" every night at bedtime, she'll figure out what you mean.


Source
http://www.parents.com/toddlers-preschoolers/development/language/teaching-second-language/
http://www.early-advantage.com/articles/monolingualparents.aspx