Babies begin learning language from sounds in the womb, as studies have shown their heart rate decreases in response to their mother's voice. After birth, they start babbling and imitating sounds, which helps them learn to speak. By 1 year old, babies can recognize words and have a vocabulary of 50 words, though they cannot say the words yet. Between ages 2-3, children experience a vocabulary spurt where they learn many new words each day and start combining words and using basic grammar. Throughout childhood and beyond, language skills continue developing as vocabulary and grammar knowledge expands.