Your toddler at 18 to 24 months: development, milestones and what to expect

18 to 24 months · Development · Updated July 2026 · All articles

The stretch between 18 and 24 months is one of the most astonishing in your child's life. Language arrives almost overnight. Big emotions appear just as fast. Your toddler is building opinions, preferences and a sense of who they are, all while their small body is learning to run, climb and kick. It is exhilarating and exhausting in equal measure.

It can also feel uncertain. Tantrums. Separation anxiety. Unpredictable naps. Sleep that worked last month suddenly does not. All of this is normal, and all of it passes.

This guide covers every area of development across these six months, drawing on the American Academy of Pediatrics (AAP) 2022 milestone guidelines, the NHS, the CDC and the Royal College of Paediatrics and Child Health (RCPCH). Milestones here describe what most toddlers are doing; development happens across a range and earlier or later is usually fine. Dip in wherever you need reassurance.

Language and communication

Of all the changes this age brings, language is the most visible. Words that seemed weeks away suddenly arrive in clusters. Understanding grows even faster than speech, and your toddler will grasp far more than they can yet say.

The AAP 2022 guidelines set six words as a meaningful floor at 18 months, but many toddlers say far more than this. By 24 months, most children have around 50 words or more, and most are beginning to put two words together: "more milk," "daddy gone," "big dog," "no shoes."

What most toddlers are doing by 18 months

What most toddlers are doing by 24 months

Worth knowing: speech at this age varies enormously. Some toddlers say 50 words at 18 months; others are closer to six or eight. What matters more than raw word count is that language is moving in the right direction, and that your toddler communicates intentionally, through words, pointing, gestures, sounds or a mix of all of these.

When to mention it to your health visitor or doctor

Hearing loss can affect language development. If there is any concern about whether your toddler can hear clearly, ask for a hearing test. It is quick and easy to arrange through your GP or health visitor.

Moving and physical development

At 18 months most toddlers are walking steadily and beginning to explore what their bodies can do. Over the next six months, movement gets faster and much bolder.

What most toddlers are doing by 18 months

What most toddlers are doing by 24 months

Falling is part of this age. Your toddler's coordination and balance are still developing, and tumbles during running and climbing are normal. They are learning what their body can and cannot do, and the best way to learn is to try.

Fine motor skills: hands and fingers

Fine motor skills involve smaller, more precise movements, and toddlers this age practise them constantly, in play, at mealtimes, during dressing and through handling everyday objects.

What most toddlers can do between 18 and 24 months

The mess at mealtimes at this age is real, and it is a sign of learning. Letting your toddler practise with a spoon or small fork, even when it takes longer and makes a mess, supports the fine motor control they are building.

Social and emotional development

This is one of the most emotionally intense periods in early childhood, and also one of the most rewarding to watch. Your toddler is becoming a full person with feelings, preferences and a sense of self. That sense of self brings friction as well as joy.

Parallel play

At 18 to 24 months, most toddlers play near other children rather than with them. This is called parallel play, and it is completely normal. They may watch what another child is doing, copy them, even play with the same type of toy side by side, but true back-and-forth play rarely happens yet. Real cooperative play, taking turns, sharing a game, collaborating on a build, typically develops closer to age three.

Tantrums

Tantrums are a hallmark of this age, and they are a sign of something developmentally healthy: your toddler has emotions far bigger than the language to express them. The frustration is real. The feeling of wanting something they cannot have, or not being able to do something they want to do, is genuinely overwhelming for a brain that is still developing the capacity to regulate emotion.

Most tantrums last two to three minutes, though some go longer. The most useful response is usually a calm presence: staying close, not reasoning during the peak of distress (the thinking brain is offline), and reconnecting warmly afterwards. Tantrums typically peak somewhere between 18 months and three years.

Separation anxiety

Many toddlers experience a peak of separation anxiety around 18 months. This is developmentally normal, a sign that your toddler has a clear and secure attachment to you and understands that you can go away. Short, warm goodbyes (rather than lingering or sneaking away) tend to help. Separation anxiety at this age usually softens through the second year, though it may flare again around new transitions like starting nursery.

Other things you might notice

Cognitive development: how your toddler thinks

Cognitive growth at this age is rapid, even though most of it is invisible. Your toddler is building an understanding of how the world works, what stays the same and what changes, what they can control and what they cannot.

Pretend play

One of the most important cognitive milestones of this period is the beginning of pretend play. Your toddler might feed a doll, put teddy to bed, talk into a toy phone or use a banana as a pretend telephone. This kind of symbolic play shows they can hold a mental image and understand that one thing can stand in for another. It is a stepping stone towards language, reading and abstract reasoning later on.

Cause and effect

By 18 to 24 months, most toddlers have a solid grasp of cause and effect. They know that pressing a button makes music play, that dropping a spoon means someone picks it up, and that pulling a tablecloth brings things on it closer to the edge. This is why toddler-proofing is so important at this age.

Object permanence

Object permanence, understanding that things exist even when you cannot see them, is fully established by this age. This is partly why separation anxiety can feel so sharp right now: your toddler knows you are somewhere; they just do not know when you are coming back.

Problem solving

You might notice your toddler trying different approaches to a problem, turning a shape until it fits, pushing a lid until it comes off, or moving a chair to reach something they want. This kind of persistent, flexible problem-solving is a sign of emerging executive function.

Symbolic thinking

By around 24 months, most toddlers can play with more than one toy at the same time in a meaningful way, putting toy food on a toy plate, or stacking one set of things while talking about another. This multi-object play shows symbolic thinking taking root.

Self-care and independence

Your toddler is becoming more interested in doing things for themselves, even when it takes three times as long and makes a much bigger mess. This drive for independence is healthy and worth supporting.

What is typical at this age

Toilet awareness

By around 18 to 24 months, many toddlers begin to show early signs of readiness for toilet training: noticing when they have done a wee or poo, pulling at their nappy, following a carer to the bathroom, or telling you they need to go shortly before or just after it happens. These are encouraging signs, but most children are not developmentally ready to begin formal toilet training until somewhere between two and a half and three years. Some are ready earlier and some later, and both are fine. There is no rush, and starting before your toddler is physically and cognitively ready tends to make the whole process harder.

The 18-month check

The 18-month check is one of the most thorough developmental reviews in the early years, and a great opportunity to raise anything you have been wondering about.

In the UK: the Healthy Child Programme review

In the UK, the 18-month review is offered to all families as part of the Healthy Child Programme and is carried out by a health visitor. It usually takes place between 18 and 24 months. The health visitor will typically:

It is worth writing your questions down before you go. It is easy to forget in the moment, and health visitors are there to help with everything from sleep to feeding to any development concern. Nothing is too small to raise.

In the US: the 18-month well-child visit

In the US, the equivalent is the 18-month well-child visit with your paediatrician. It covers similar ground: growth measurements, developmental screening (the M-CHAT-R/F is often used for autism screening at this visit), vaccines according to the CDC schedule, and time to discuss any concerns you have. This is also the visit where lead screening may be offered depending on your child's risk factors.

In Australia, the eight-visit Maternal and Child Health check at around 18 months covers development, growth, feeding and behaviour.

Sleep at 18 to 24 months

Sleep at this age is often less predictable than parents hope, but the overall pattern becomes more consolidated through the second year.

How much sleep is typical

The AAP and the NHS both recommend 11 to 14 hours of total sleep in a 24-hour period for toddlers at this age. Most of this is at night, with one daytime nap making up the rest.

The nap

By 18 months, most toddlers have transitioned from two naps to one midday nap, usually lasting one to two hours. Some toddlers make this transition earlier (from around 15 months); others take a little longer. If your toddler is fighting the morning nap but cannot quite make it to midday without becoming overwhelmed, moving lunch slightly earlier and bringing naptime forward can help bridge the gap during the transition.

Night waking

Night waking is common at this age and does not mean anything is wrong. It often increases during developmental leaps, when new teeth are coming through, during illness, or after a change in routine. It tends to ease again once the leap or disruption passes. If night waking is happening very frequently and you are exhausted, your health visitor can offer practical, non-judgemental support.

Around 24 months

Some toddlers start to resist naps or nap for shorter periods as they approach their second birthday. If this happens, a quiet rest time in their room or cot, even if they do not sleep, helps regulate their energy and mood through the afternoon. Naps often continue until around three years, so it is worth holding on to them if your toddler still needs one.

Bedtime

Most toddlers do well with a bedtime between around 7pm and 8pm, though this varies by family. A consistent, calm bedtime routine, bath, milk, books, a song, a few minutes of quiet connection, signals the shift to sleep more reliably than any clock time.

Play ideas for this age

Play is how toddlers learn, and between 18 and 24 months they can engage with a much wider range of activities than before. The best play at this age is usually simple, open-ended and involves you some of the time.

Screen time guidance from the AAP recommends avoiding screen use for children under 18 months (other than video calls) and limiting screen time to one hour a day of high-quality content for children aged 18 to 24 months, with a parent watching alongside. Co-viewing means you can name, explain and extend what they are seeing.

When to talk to your health visitor or doctor

Development happens across a wide range, and most differences in timing are nothing to worry about. But it is always worth getting a professional opinion if you notice any of the following. Health visitors and paediatricians would always rather hear a concern and reassure you than miss something that could benefit from early support.

At 18 months, mention it if your toddler

At 24 months, mention it if your toddler

If an autism spectrum condition is something you are wondering about, the 18-month check includes screening questions for this, and your health visitor or doctor can refer for further assessment if needed. Early support for autism, when accessed, is genuinely beneficial.

Trust your instincts. You know your toddler better than anyone. If something feels off, raise it, even if you cannot articulate exactly what it is.

Frequently asked questions

When should my toddler be talking?

Most toddlers say at least six words by 18 months, and many say far more. By 24 months, most children have 50 or more words and are beginning to put two words together, like "more milk" or "daddy gone." If your toddler has fewer than six words at 18 months, or is not combining any words by 24 months, mention it to your health visitor or doctor. Speech and language therapy is effective and accessible when it is needed.

What if my toddler is not walking at 18 months?

Most children walk independently by around 12 to 15 months, and nearly all are walking well by 18 months. If your toddler is not walking at all by 18 months, it is worth raising with your health visitor or doctor so they can check there is nothing that needs investigating. Bottom-shufflers sometimes walk a little later than cruisers, and this is usually fine, but your health visitor can advise based on the full picture.

Is it normal for my toddler to play alone and ignore other children?

Yes, completely. Toddlers at this age mostly do parallel play, playing near other children but not really with them. They may watch each other, copy each other and enjoy being together, but taking turns and collaborating on a game come later, typically closer to age three. Parallel play is healthy and entirely expected at 18 to 24 months.

When should I worry about tantrums?

Tantrums are very normal at this age and often peak between 18 months and three years. They are mostly a sign of frustration when language cannot yet match emotion. Speak with your health visitor or doctor if tantrums are very frequent (more than five a day), last more than 25 minutes, involve your toddler hurting themselves or others regularly, or feel like they are escalating over time rather than settling. Your health visitor can also offer strategies if tantrums are making daily life very difficult.

What does the 18-month check involve?

In the UK, the 18-month Healthy Child Programme review is carried out by a health visitor. They will check weight and height, talk through development across language, movement and social skills, and use a developmental screening questionnaire that includes questions screening for autism (M-CHAT-R/F or ASQ-3). They will also ask about your own wellbeing. Vaccines are given at this visit in the UK. In the US, the equivalent is the 18-month well-child visit with your paediatrician, which covers similar ground.

How much sleep does an 18-month-old need?

Most toddlers at 18 to 24 months need around 11 to 14 hours of sleep in total across the day and night. One midday nap of one to two hours is typical at this age. Night waking is common, especially during developmental leaps or when a toddler is unwell or cutting teeth. If you are struggling with sleep, your health visitor is a good first port of call.

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