Research shows that babies build knowledge about the language they hear in the first few months of their lives.

According to the study, if a person moves countries and forgets their birth language, they still retain this hidden ability to identify the language.

In the study, Dutch-speaking adults adopted from South Korea exceeded expectations at Korean pronunciation after losing their birth-language.

"This finding indicates that useful language knowledge is laid down in the very early months of life, which can be retained without further input of the language and revealed via re-learning," said Dr. Jiyoun Choi of Hanyang University in Seoul, who led the research.

In the study, adults aged about 30, who had been adopted as babies by Dutch-speaking families, were required to pronounce Korean consonants after a short learning period.

The test subjects were then compared with another group who had not been in contact with the Korean language as children.

The two groups were rated by native Korean speakers.

Both groups underwent the same level of training. But after the training, the international adoptees performed well beyond the expectations.

There was no disparity between children who were adopted before they could speak at less than six months of age, and those who were adopted after 17 months after having already learned how to speak.

The study suggests that the language knowledge retained is not dependent on the amount of individual experience, but is abstract in nature.

Dr. Jiyoun Choi said that this sends a practical message to parents. According to Choi, Parents should remember that the language learning process occurs very early in life.

Dr. Choi urged parents to try and talk to their babies as much as possible because the babies absorb and digest every word that comes out the parent's mouth.