Babies start making sentences in stages: around 2 years, they first put two words together, such as “more milk”. Around two and a half, they combine two or more words including an action word. By 4 years, most children say sentences of four words or more. These ages come from the milestones of the CDC (Centers for Disease Control and Prevention, the US public health agency), which are reached by at least 75% of children.
Between these milestones, the differences are wide and usually nothing to worry about. This article walks through each stage, what helps your child build their first sentences, and the signs that are worth raising with your doctor.
At what age do babies start making sentences?
The first two-word combinations generally appear between 18 months and 2 years. At 2 years, the CDC sets this milestone: the child “says at least two words together”. This isn’t yet a grammatical sentence, but an idea expressed with two words instead of one.
Sentences with a verb come next. At 30 months, the CDC milestone becomes “two or more words together, with one action word”, such as “doggie run”. Sentences of four words or more appear in the 4-year milestones.
These milestones are thresholds reached by at least three children out of four. So one child in four gets there later, often without any particular difficulty.
The stages, from first word to real sentence
Before 18 months: one word to say a whole sentence
First words often arrive around 12 months. A single word then carries a whole intention: “water” can mean “I want some water” just as much as “look, water”. Gestures, eye contact and tone of voice complete the message. Pointing plays a big part here, as we explain in our article on babies pointing.
From 18 months to 2 years: two words together
Vocabulary grows quickly and the first combinations appear: “daddy gone”, “more biscuit”, “no nap”. The little linking words are still missing. Word order is often already right, which shows that the child has grasped part of the structure of the language.
At 2 years, the CDC also lists other communication milestones. The child points to pictures in a book when asked and points to at least two body parts. They also use gestures beyond waving bye-bye, such as blowing a kiss.
Around two and a half: the verb joins the sentence
The CDC milestone at 30 months mentions about 50 words. The child combines two or more words including an action word, names things in a book and uses “I”, “me” or “we”. Switching from their own name to “me” is a real turning point: the child talks about themselves as a person who does things.
Around 3 years: conversation
At 3 years, the CDC notes that the child keeps up a conversation of at least two back-and-forth exchanges. They ask “who”, “what”, “where” or “why” questions. This marks the start of the “why” phase. They describe the action in a picture, such as “he’s eating”, and say their first name when asked. They speak well enough for others to understand them most of the time.
Around 4 years: longer sentences and stories
The 4-year milestones include sentences of four words or more. The child talks about at least one thing that happened during their day and repeats words from a song or a story. They also answer simple questions about what things are used for.
Why some children make sentences later
The pace of language development varies a great deal from one child to another. Some collect single words for months, then suddenly start combining them. Others talk early but stick to short sentences for a long time. Understanding often moves ahead faster than speaking: a child who understands simple instructions already has a lot of language in their head.
Our article on babies understanding simple instructions helps you observe this side, less visible but essential.
The big picture, from babbling to the vocabulary explosion, is in our article on language development from 0 to 3 years. This article focuses on the step from word to sentence.
How to help your baby make sentences day to day
The levers are simple and need no equipment. They rely on interaction, not drills. The ideas below reflect common parenting practices, in line with the recommendation to talk to your child a lot.
Repeat what they say, adding a word
When your child says “lorry”, reply “yes, a big lorry”. When they say “lorry gone”, reply “the lorry went off quickly”. You’re showing them the next sentence without asking them to repeat it. It’s the most natural and most useful technique at this age.
Describe what they’re doing
Put words to what’s happening: “you’re filling the bucket”, “you’re climbing onto the chair”. These little sentences go along with the action and give meaning to verbs. Our article on why talking to your child from birth matters shows how to weave talking into care routines and mealtimes.
Read together, and let your child fill in the gaps
Picture books offer the ideal setting: you point, you name, you ask a question, you wait. With a familiar book, let your child finish the sentence. Our guide to reading a book to your baby covers the right formats for each age.
Give them time to answer
After a question, count to five in your head before speaking again. Many children need this pause to organise their words. Offering a choice helps too: “do you want the apple or the banana?”
Sing and repeat nursery rhymes
Nursery rhymes build the rhythm of sentences and the little linking words. The child first picks up the ending, then whole passages. This pleasure in repetition paves the way for longer sentences.
Limit screens in the background
A television left on reduces the interaction between adult and child, even when nobody is watching it. The data and recommendations are covered in detail in our article on screens before age 3.
What doesn’t help
- Making them repeat a correct sentence: the child shuts down more than they learn.
- Correcting them all the time: use the right form in your reply, without pointing out the mistake.
- Speaking for them when they’re searching for words, or anticipating all their needs before they express them.
- Comparing them with a cousin or a child from nursery: every child follows their own path.
When should you talk to your doctor?
The CDC recommends talking to your doctor as soon as a child doesn’t reach an expected milestone for their age, without waiting. In practice, several situations call for an appointment:
- at 2 years, the child never puts two words together;
- at 30 months, they don’t say any sentence with a verb and their vocabulary remains very limited;
- at 3 years, people outside the family can’t understand them most of the time;
- at any age, they lose words or skills they once had;
- they don’t seem to hear, don’t respond to their name or don’t try to communicate.
The doctor will check hearing in particular, as well as overall development. Our article on spotting neurodevelopmental disorders before age 3 explains the process in France. An isolated language delay is common and often catches up, but it’s better spotted early than late.
Key takeaways
Babies make two-word sentences around 2 years, add a verb around two and a half, hold conversations at 3 and make their sentences longer around 4. These milestones are reached by at least 75% of children: a gap of a few months is nothing to be alarmed about. To help, talk with your child, build on their sentences without correcting them, read together and give them time to answer. And if in doubt, talk to your doctor without waiting.
Sources
- Centers for Disease Control and Prevention (CDC), “Milestones by 2 Years”, page reviewed on 16 May 2026.
- CDC, “Milestones by 30 Months”, page reviewed on 16 May 2026.
- CDC, “Milestones by 3 Years”, page reviewed on 16 May 2026.
- CDC, “Milestones by 4 Years”, page reviewed on 16 May 2026.
