4 to 6 months

Every baby is different. These are things most babies (at least 3 in 4) do by the end of this stage. If your baby was born more than 3 weeks early, take the weeks they were born early off their age, and use that age here until their 2nd birthday.

What to expect

Listening and understanding

Turns their head toward the sound of your voice
Reacts to toys that make sounds, like bells or music
Responds to your facial expressions
Knows familiar people

Making sounds

Coos ("oooo", "aahh") and makes sounds back when you talk to them
Makes long vowel sounds, sometimes with a consonant, like "aaagoo" or "daaa"
Blows raspberries and squeals
Takes turns making sounds with you
Makes sounds while playing, even with something in their mouth

Playing and connecting

Smiles on their own to get your attention
Chuckles, then laughs
Looks at you, moves or makes sounds to get or keep your attention
Looks at things that interest them and follows them with their eyes

Eating and drinking

Opens their mouth when hungry and they see the breast or bottle
Brings their hands to the breast or bottle, and pats it
Brings hands and toys to their mouth to explore them
Starts to hold the bottle or breast during feeds
Closes their lips to show they don't want more

Starting solid food

Your baby only needs breast milk or formula for now. Solid food starts at around 6 months, once your baby is also showing they're ready: holding their head up steadily without support, sitting upright without support, reaching out and grabbing things, and moving food from the front of their mouth to the back and swallowing it. Interest in your food on its own isn't enough.

Growing up with two languages

Speak to your baby in the language or languages you're most comfortable using. Babies this age watch your mouth as well as listen. In one study, 4- and 6-month-olds could tell English and French apart just from watching silent videos of people speaking. At 8 months, babies growing up with both languages still could, while babies hearing one language no longer did.

Get medical help straight away if, during a feed, your baby:

has difficulty breathing (for example grunting, or sucking in their tummy when they breathe); has lips, tongue or skin turning blue, grey or very pale; or is choking and their cough is silent or they can't breathe in properly. Call your local emergency number.

If your baby is choking: follow the first-aid steps for babies under 1 on the NHS choking first-aid page.

Talk to a professional if your baby...

Isn't doing many of the things on this page by the end of this stage
Often coughs during or after feeds
Arches their back or cries during most feeds
Brings up more than ordinary spit-up
Often loses milk from their mouth while feeding
Is often very sleepy during or after feeds
Is having any trouble breastfeeding or bottle-feeding. You don't need to wait.

Worried about your baby's hearing? Ask for a hearing test, even if your baby responds to some sounds. You don't need to wait for other signs.

When to talk to someone

You don't need to wait until several things are missing. Talk to a professional if your baby isn't doing many of the things on this page by the end of this stage, if you have any one specific worry (such as their hearing, losing skills they had, their communication or their feeding), or if you're simply worried. You know your baby best.

Who to talk to

Your health visitor, GP, paediatrician or a speech and language therapist.

Help your baby

Play back and forth: when your baby smiles, smile back, and when they make sounds, copy them
When your baby looks at something, point to it and name it
Look at picture books together and answer when they babble
Play peek-a-boo and watch for their smile
Keep screens to video calls with family

Where this information comes from

Research references

Weikum et al. (2007), Visual Language Discrimination in Infancy, Science