3–6 months

Coos & Curiosity

The first real back-and-forth — a coo, a smile, a look that lasts.

Somewhere around the third month, most babies become noticeably more "there" — holding eye contact, tracking faces across a room, and trading the reflexive cries of the newborn stage for real cooing: long, deliberate vowel sounds that are their first genuine attempts at vocal play. Babies this age are also becoming excellent listeners for pitch and turn-taking, even though true babbling and back-and-forth games are still a few months off. This is the stage to start responding to baby's coos as if they were a conversation — pausing, reacting, cooing back — and to narrate with even more expression, since baby can now actually watch your face while you do it. Parents are still very much the ones doing the learning here; the goal is simply staying consistent as baby's attention window grows.

• Responding to coos as if they're 'talking back'
• Exaggerated facial expression — baby can track your face now
• Longer stretches of narration as baby's attention grows
• Still input-only; parents keep building their own phrases