Baby Development and Milestones by Age (0 to 2 Years)

Last updated: November 2026. Figures checked against the official sources listed at the end of this page on October 2, 2026.

Short answer: According to the Canadian Paediatric Society, by the end of 3 months most babies smile back and roll from front to back; by 8 months most sit on their own and roll both ways; at 12 to 14 months most pull up to stand and say "mama" or "dada" with at least one other word with meaning; and at 18 months most walk alone and say 20 or more words.

Key facts

Fact Figure Source
By 3 months Smiles back, rolls front to back CPS
By 8 months Sits alone, rolls both ways CPS
12–14 months Pulls to stand; "mama"/"dada" + 1 other word with meaning CPS
18 months Walks alone, 20+ words CPS
24 months Begins to run, starts 2-word phrases CPS

Every child develops at their own pace. The Canadian Paediatric Society's guide groups milestones by age and says it is normal for a child to be ahead in some areas and behind in others. For babies born early, use their corrected age (actual age minus the weeks or months they were born early).

Jump to: By the end of 3 months · By the end of 8 months · At 12 to 14 months · At 18 months · At 24 months

By the end of 3 months, most babies can:

  • Movement: rolls from front to back, controls head and neck when sitting, raises head and chest when lying on their stomach, kicks, and pushes down with their legs when their feet are on a firm surface.
  • Hands: brings hands together and to the mouth, opens and shuts them, swipes at hanging objects.
  • Social and language: smiles when you smile and on their own, watches faces closely, copies some movements and expressions.
  • Thinking: follows moving objects and recognizes familiar people and things.

Play ideas: Unbreakable mirrors, peek-a-boo cloths, soft wrist rattles and toys with faces (CPS playtime ideas for birth to 3 months).

By the end of 8 months, most babies can:

  • Movement: rolls both ways, sits on their own, supports their whole weight on their legs, controls upper body and arms.
  • Hands: holds and shakes a toy, moves an object from hand to hand, explores with their hands.
  • Social and language: reaches for familiar people, smiles at themselves in a mirror, copies speech sounds.
  • Thinking: finds a partly hidden object, watches a falling object, struggles to get objects that are out of reach.

Play ideas: Sturdy rattles, large grasping rings, play arches and textured fabrics; from 6 months, a set of nesting cups and some sturdy blocks (CPS).

At 12 to 14 months, most babies can:

  • Movement: reaches a sitting position without help, crawls or bum-scoots, pulls up to stand, cruises holding furniture; may take 2 or 3 steps alone.
  • Hands: finger-feeds with thumb and forefinger (pincer grasp), puts objects into a container and takes them out, begins to drink from a cup and use a spoon.
  • Social and language: says "mama" or "dada" with at least one other word with meaning, responds to their name, may be shy or anxious with strangers.
  • Thinking: explores objects by shaking, banging, throwing and dropping; knows the names of familiar objects; begins to explore cause and effect.

Play ideas: Stacking and nesting toys, board books, shape sorters, push toys and simple percussion instruments (CPS 6 to 12 months).

At 18 months, most babies can:

  • Movement: walks without help, climbs into chairs, climbs stairs one at a time with help.
  • Hands: builds a 3-block tower, uses a spoon well, turns a few board-book pages at a time.
  • Social and language: says 20 or more words, follows a simple instruction, points to a named body part.
  • Thinking: uses objects as tools and fits related objects together, such as in a shape sorter.

Play ideas: Shape sorters, chunky puzzles, board books and pretend-play items such as a toy broom or phone.

At 24 months, most babies can:

  • Movement: begins to run, kicks or throws a ball, walks up and down stairs with help, pulls a toy while walking.
  • Hands: builds a tower of 4 or more blocks, completes a simple shape-matching puzzle, turns pages one at a time.
  • Social and language: starts to put 2 words together, plays alongside other children, copies adults and other children.
  • Thinking: begins make-believe play and shows increasing independence (and some defiance).

Play ideas: Pull toys, balls, simple puzzles and make-believe sets.

When to talk to your health-care provider

The CPS advises speaking with your doctor if you have any concerns about your child's development, or if they seem to be behind in more than one area. You do not need to wait for a scheduled check-up.

Milestone summaries are paraphrased from the Canadian Paediatric Society handout "Your child's development: What to expect" (last updated October 2019); play ideas from its "Playtime with your baby" handout (July 2022). We merged our 14 month-by-month milestone pages into this guide.

Frequently asked questions

When do babies sit up on their own?

The Canadian Paediatric Society lists sitting on their own among the skills most babies have by the end of 8 months.

When do babies start walking?

At 12 to 14 months most babies cruise along furniture and may take 2 or 3 steps alone; by 18 months most walk without help.

How many words should an 18-month-old say?

The CPS lists 20 or more words as typical at 18 months.

What if my baby was born early?

Use corrected age: your baby's actual age minus the number of weeks or months they were born early.

When should I worry about my baby's development?

Talk to your doctor if you have any concern, or if your child seems behind in more than one area.

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Related guides and tools

Sources

  1. Canadian Paediatric Society (Caring for Kids): Your child's development – What to expect (checked October 2, 2026)
  2. Canadian Paediatric Society (Caring for Kids): Playtime with your baby (checked October 2, 2026)

This page is general information, not medical advice. Follow your child's health-care provider and the product manufacturer's instructions.