While not every child develops speech and language on the same timetable, the National Institute on Deafness and Other Communication Disorders does provide a list of age-appropriate speech and language milestones for babies and young children.

If you suspect your child is failing behind his peers, consult your child’s doctor or schedule a speech and language evaluation for your child.

Milestones related to speech and language

Birth to 3 months

• Seems to know your voice and quiets down if crying
• ​Reacts to loud sounds with a startle reflex
• Is awakened by loud voices and sounds
• Vocalizes pleasure and displeasure sounds differently (laughs, giggles, coos, cries, or fusses
• Makes noise and smiles when spoken to
• Responds to sound of rattle

4 to 6 months

• Looks or turns toward a new sound
• Responds to “no” and changes in tone of voice
• Enjoys rattles and other toys that make sounds
• Vocalizes back when talked to
• Begins to repeat sounds (such as, “ooh,” “aah,” and “ba-ba”)

7 to 11 months

• Responds to his or her own name, telephone ringing, or someone’s voice even when not loud
• Knows words for common things (such as, “cup” or “shoe”) and sayings (such as, “bye-bye”)
• Babbles (says "ba-ba-ba," "ma-ma" or "da-da")
• Tries to communicate by actions or gestures
• Looks at things or pictures when someone talks about them
• Starts to respond to requests (such as, “come here”)
• Enjoys games like peek-a-boo and pat-a-cake
• Makes babbling sounds, even when alone
• Imitates simple words and sounds; may use a few single words or baby signs meaningfully

12 to 17 months

• Understands simple phrases (such as, “put the ball in the box” or “put the car on the table”)
• Enjoys being read to
• Follows one-step commands when shown by a gesture
• Answers simple questions by shaking his/her head or going to get an item when asked
• Says two to three words to label a person or object (pronunciation may not be clear)
• Tries to imitate simple words
• Vocabulary includes four to six words or more
• Says more words as each month passes

18 to 23 months

• Understands the meaning of action words (such as clap, sit or jump)
• Points to some body parts when asked
• Understands and answers simple “yes-no” questions (such as, “Are you hungry?”)
• Understands “not now” and “no more”
• Chooses things by size (such as, “big” or “little”)
• Uses a vocabulary of 50 words, pronunciation is often unclear
• Asks for common foods by name
• Makes animal sounds (such as, "moo")
• Starts to combine words into 2- to 3-word phrases to talk about and ask for things (such as, "more milk")
• Begins to use pronouns (such as, "mine")

2 to 3 years

• Knows some spatial concepts (such as "in" or "on")
• Understands and uses more pronouns (such as, "you," "me" or "her")
• Knows descriptive words (such as, "big" or "happy")
• Answers many simple questions
• Follows two-step commands (such as, “Get your shoes and come here.”)
• Uses three- to four-word sentences
• Uses at least 100 words by 2 years of age
• Uses question inflection to ask for something (such as, "My ball?")
• Begins to use plurals, such as "shoes" or "socks" and regular past tense verbs (such as, "jumped")
• Speech pronunciation is improving, but may still leave off ending sounds; strangers may not be able to understand much of what is said

3 to 4 years

• Answers simple questions (such as, "What do you do when you are hungry?")
• Groups objects into categories (such as, foods or clothes)
• Recognizes colors
• Uses 300 to 500 words by 3 years of age
• Describes the use of objects (such as, "You eat with a fork")
• Has fun with language; enjoys poems and recognizes language absurdities such as, "Is that an elephant on your head?")
• Expresses ideas and feelings rather than just talking about the world around him
• Uses verbs that end in "ing" (such as, "walking" or "talking")
• Uses most speech sounds, but may distort some of the more difficult or later developing sounds, (such as l, r, s, sh, ch, v, z, th)
• Uses consonants in the beginning, middle, and ends of words. Some of the more difficult consonants may be distorted, but tries to say them
• Strangers are able to understand much of what is said

4 to 5 years

• Answers "why" questions
• Lists items that belong in a category (such as, animals or vehicles)
• Understands more abstract spatial concepts (such as, "behind" or "next to")
• Understands complex questions
• Uses some irregular past tense verbs (such as, "ran" or "fell")
• Describes how to do things (such as, painting a picture)
• Speech is understandable, but makes mistakes pronouncing long, difficult, or complex words (such as, "hippopotamus")

5 years

• Understands time sequences (such as, what happened first, second, or third)
• Carries out a series of three directions
• Understands rhyming
• Engages in conversation
• Produces sentences that can be eight or more words in length
• Uses compound and complex sentences
• Describes objects
• Uses imagination to create stories