Overview

Children usually progress from one developmental milestone to the next. But each child grows and gains skills at their own pace. Some children may be advanced in one area, such as language, but behind in another, such as sensory and motor development.

Milestones usually are grouped into five major categories: physical growth, cognitive development, emotional and social development, language development, and sensory and motor development.

Physical growth and development

Most children by age 2:

• Have grown about 15 in. (38 cm) since birth.
• Gain weight and grow at a steady but slower pace than during their first 12 months of life. Between 12 and 24 months of age, expect your child to gain about 3 lb (1.5 kg) to 5 lb (2.5 kg), grow an average of 3 in. (7.5 cm) to 5 in. (13 cm), and gain about 1 in. (2.5 cm) in head circumference. (This is the measurement around the top of the head.) Go to www.cdc.gov/growthcharts to view standard growth charts.

Thinking and reasoning (cognitive development)

Most children by age 2:

• Start to understand simple time concepts, such as "now," "later," or "a few minutes." (The distant future or "forever" are too complex to understand at this age.)
• Follow simple requests, such as "Put the book on the table." But two-step instructions, such as "Wash your hands, and come here," usually cannot be completed.
• Recognize basic symbolism, such as nodding the head for yes or no.
• Often want to do two incompatible things at the same time. For example, a 2-year-old may want to go out in the snow while wearing slippers.
• Start to play "pretend," such as by talking on a toy telephone.
• Start to recognize and sort objects by shape and color.

Emotional and social development

Most children by age 2:

• Are developing self-awareness, the realization that they are individuals and are separate from other people. Children are excited by their developing skills. But they also often struggle with their emerging independence. Your child may resist your comforting one minute, only to run clinging to you the next. They understand and use the word "no" as a way to assert themselves. Sometimes calmly redirecting your child or stating the request in a different way will help this behavior. But a child can also stubbornly resist direction. Temper tantrums reflect related frustrations and competing feelings.
• Are aware that they may not always get what they want or that they may have to wait for it. Many children also start to see a relationship between how they act and what happens next. But they often act on impulse. They often don't behave consistently, because they can't yet completely anticipate the consequences of their actions.
• Like to observe and imitate other people.
• Are interested and excited about being with other children. But they still engage in parallel play. This means playing next to, but usually not with, other children. They usually haven't mastered sharing and other cooperation skills.
• Aren't concerned about gender differences, but start to recognize that they exist.

Language development

Most children by age 2:

• Use at least 50 words.
• Put two words together, such as "no bottle."
• Name some body parts and familiar objects, such as "toy" or "cat."
• Speak with a mix of made-up words and understandable words.
• Repeat words they overhear, such as from adult conversations.

Sensory and motor development

Most children by age 2:

• See and hear well.
• Are quickly developing motor skills. Around the second birthday, children can usually go up and down stairs one step at a time and kick a ball, and they are starting to run. Most children can also stand on their tiptoes. You may see your child carrying toys, sometimes large toys, around the house. Pull-toys are also a favorite around this age.
• Scribble and draw simple strokes with a crayon. They can also pour out toys or other objects from a container and build a tower with 4 or more blocks. You may notice your child using one hand more than the other.