• 3 months
• 6 months
• 12 months
• 15 months
• 18 months

• 21 months
• 2 years
• 3 years
• 4 years
• 5 years

• make noises (eg., coos, gurgles)
• turn towards a new sound
• jump at a loud noise
• be calmed when you speak in a gentle voice
• smile at you 

When to call for help:

• Your baby does not react to your voice or other sounds.
• Your baby does not smile or make sounds when awake

• watch your face when you talk
• cry in a different way when hungry
• make noises to get attention
• make sounds back when you talk
• smile at you and other family members

When to call for help:

• Your baby does not react to your voice or other sounds.
• Your baby does not smile or make sounds when awake.

• understand their own name
• understand words like "bye-bye" or "up"
• say sounds like "ba ba, na na, ga ga"
• laugh and try to make sounds like you do
• say their first word

When to call for help:

• Your baby does not wave
  back at you when you say "bye bye" and wave.
• Your baby does not try to show  you things by
  reaching,  looking, or pointing.
• Your baby does not use a lot of sounds and/or
  does not copy sounds mouth movements
  (eg. "rasberry") that you make.

• take turns making sounds
• say 2 or 3 words, but not clearly
• understand "no" and shake their head
• reach or point to something they want while making a sound
• understand simple questions or directions like "where is your nose?", "show me your shoe".

When to call for help:

• Your child does not try to say words, make sounds or gestures to tell you what he or she wants.
• Your child does not follow simple directions even with assistance.
• Your child does not try to get your attention by pointing to things.

• understand words and point to parts of their bodies like "nose, ear"
• look for things when asked
  to, like "get your hat"
• make new gestures and/or
  words like you do
• make gestures or ask for
  "more" or "again"
• Says lots of words

When to call for help:

• Your child does not make sounds or gestures like you do.
• Your child started to use words, but stopped.
• Your child uses less than 10 words.
• Your child is not playing with toys for pretend purposes. (eg. pretending to talk on
  the phone).

• point to a picture or sign, such
  as when asked "Where's
  McDonalds?"
• play with toys and pretend
  to do thingslike feeding a
  doll or going in a car
• say at least 20 or more words
• follow directions such as
  "drink your juice" or "sit
  down please"

When to call for help:

• Your child only says less
  than 20 words
• Your child does not
  pretend with toys.

• understand more than they can say
• say two words together like "more milk"
• ask "what¹s that?" (may sound like "wha dat" or "whatssat")
• pick one thing out from a group of objects, such as a cup.
• begin to follow longer directions 

When to call for help:

• You have a hard time understanding what your child says.
• Your child uses fewer than 50 words or does not put two words together.

• use short sentences, like "me do it", "daddy going car"
• follow simple directions, like "put the teddy bear to bed"
• place something in the right spot if you say to put it "in", "on" or "under"
• have a conversation with family members or other familiar people
• listen to stories and answer simple questions
• begin to add endings to words, such as running, toys

When to call for help:

• Your child acts frustrated when
  trying to talk.
• You have a hard time understanding what your child says.
• Your child does not string together several words to make sentences.
• Your child finds listening to a 10 minute storybook challenging

• use sentences of 4 to 6 words
• give directions like "fix this for me"
• ask many questions like what, where, why
• tell about things they have done
• talk to themselves and their toys
• tell a story or sing a song
• tell you when they are tired

When to call for help:

• Your child repeats words but does not seem to understand.
• Your child stutters.
• Other people have a hard time understanding what your child says.
• Your child uses words in an unusual way
• Your child finds it difficult to talk about or re-tell past events.
• Your child is not interested in books

• use sentences that sound almost like an adult
• be able to say most speech sounds correctly
• explain what familiar words mean
• use sentences to describe objects and events
• explain how to solve a simple problem
• follow related directions, like "get your crayons, make a picture and put it on the fridge"

When to call for help:

• Your child does not use complete sentences.
• Your child does not like talking to other children.
• Your child has trouble following directions.
• Your child has not begun to play with
  sounds in words and make rhymes.
• Your child cannot repeat or sing songs with  rhyme or pattern.