3-year-olds:

• Follow two-part requests, such as "put your pajamas in the hamper and your slippers in the closet."
• Learn new words quickly; know most common object names.
• Understand the concept of "two."
• Understand gender differences.
• Know their own full name.

• Start to correctly use plurals, pronouns, and prepositions more consistently.
• Often ask "why" and "what."
• Often use complete sentences of 3 to 4 words.

4-year-olds:

• Know the names of colors.
• Understand the difference between things that are the same and things that are different, such as the difference between children and grown-ups.
• Can follow three-step instructions, such as "Go to the sink, wash your hands, and dry them on the towel."

• Use the past tense of words.
• Use sentences of 5 to 6 words.
• Can describe something that has happened to them or tell a short story.
• Can speak clearly enough to be intelligible to strangers almost all of the time.

5-year-olds:

• Understand relationships between objects, such as "the girl who is playing ball" and "the boy who is jumping rope."

• Usually can carry on a conversation with another person.
• Often call people (or objects) by their relationship to others, such as "Bobby's mom" instead of "Mrs. Smith."
• Can define words such as "spoon" and "cat."