Immersion. Young children are surrounded by language as it is used by others in their environmenl. Beginning al birth, children hear the conversations of Uieir parents, siblings, and 0U1ers in their environment.
Every language teacher will argue that immersion is the best way to learn a language because it is all around you and your brain begins to comprehend the language that you're constantly hearing. It's cool because we don't think about being immersed in our native language as babies.