Learning more than just one language is absolutely an advantage. For preschoolers, this is the best time to take it all in, but don't rely too much on language books, tapes and even weekly classes. The best and proven way is to have a conversation with a native speaker, since repetition helps the brain the most for a child to become more fluent.
Making new neural connections in their brains, children learn languages more easily at a very young age, at an age when they begin to talk. Hearing all the unique sounds and tones of a different language will easily make them catch it faster in comparison to an older child or an adult. Being bilingual has also shown to have lasting cognitive benefits. But to retain a second language, it has to be heard constantly, preferably on a daily basis. If the child grows up being less exposed to that language, then there is a huge possibility that he/she will not be proficient or fluent. It's just the way it is. If anyone else in your household (including the staff) speaks another language apart from yours, do try to encourage your child to learn it, as well. Again, that could be another big advantage for your little one in the future.
Myths About Bilingualism
1.Being bilingual can cause language delay. FALSE. A bilingual child's vocabulary may be smaller than average, but the total vocabulary (from both languages) is the same size as a monolingual child.
2.Mixing a language means the bilingual child is confused and will have trouble speaking. FALSE. This is by far a misconception! It is a natural part of bilingualism, known as "code mixing" or "code switching" but this however is not a sign of language delay. It is actually expected to code-mix most especially when speaking to other bilingual children.
3.Being bilingual means being proficient in the two languages. FALSE. There will always be a dominant language but this can change with age, education, social network, circumstance, etc
4.If you want your child to speak another language but not your own mother tongue, then you should stop speaking that language to your child. FALSE. Conversations and interactions will feel very unnatural to both the parent (especially if the language is his/her mother tongue) and the child (who might learn something else incorrectly). Plus, it is also very important for a child to take pride in his/her own heritage, no doubt about that.
5.It's never too late to raise your child bilingual. IT DEPENDS. From birth to 3 years old, the mind is still open and flexible since this is a time in a child's life when they are taking everything in and actually "learning" a language/s. This is the easiest time for a child, just like a sponge, they absorb everything so quickly. Between 4 to 7 years old, they are able to process the language on parallel paths. From 8 years old to puberty, languages are stored on a separate area of the brain and they use their native language to translate to the "new" language they are learning.
Helpful Resources:
www.babycentre.com
www.hanen.org