Here's why:
* Universal Language Learning Capacity: Babies are born with a universal language learning capacity, meaning they can distinguish between all the sounds of all languages. This is known as phonetic discrimination.
* Critical Period: This capacity starts to decline around the age of 12 months. After that, it becomes much harder to learn a language with native-like proficiency. This is referred to as the critical period.
* Exposure and Experience: Babies learn language through exposure and interaction. The more exposure they have to a language, the better they will be able to learn it.
* Brain Development: As babies are exposed to a language, their brains develop pathways that are specific to that language. This makes it easier for them to understand and speak that language.
In short: Babies are not born with pre-loaded languages, but they have a remarkable ability to learn any language within a certain timeframe, depending on their exposure and experience.