Speech development cannot be separated from language development and vocal development in children. Children must learn not only to make the correct sounds with their lips, jaws and tongues, they must understand the rules of communication and be able to follow them. But as complicated as that sounds, there are simple checklists that parents can use to assess their children's speech development. The American Academy provides a general checklist for infants and toddlers, while The American Speech-Language-Hearing Association has a yearly list for children from birth through fifth grade.
Even though infants can't speak, there are still skills parents can assess. By 3 months old, your little one should be cooing at you. By 6 months, he should be babbling with consonant sounds, gurgling and vocalizing her feelings of pleasure or unhappiness. Before your infant is 1 year, he should use his speech sounds instead of only cries to get your attention.
Around the first birthday, speech really starts to take off. Your toddler should be saying at least a few actual words, as well as babbling with intonation. He should take turns "talking" with you, even if you're the only one using actual words. Around 18 months, he should learn one new word each week. He should also start being able to follow simple directions and put two words together, such as "more juice" or "go bye-bye". Your little one will also get much better at using gestures to communicate; such as pointing at things he wants. Consonant sounds at the beginning of words will grow stronger each month, as well.
Your 2-year-old should be able to use between 50 and 100 words and several two word phrases. He may even have a few three word sentences. Familiar adults will understand him most of the time and he will take advantage of this by naming things he wants or wants you to notice. He should be able to clearly say the consonant sounds k, g, f, t, d, and n.
Your preschooler can tell you what happened at school, what he wants for lunch and what he wants to play - all without taking a breath! Between 3- and 4-years old, your little one will start talking in sentences consistently and clearly. He won't repeat syllables or words very often, and even unfamiliar people will understand much of what he says. As he heads towards 5, he will be able to communicate with others easily. His stories will stick to a basic topic and his sentences will have details. He will be able to say all the language sounds except l, s, r, v, z, ch, sh, th. He will even use the same grammar as the adults he knows.
Early Elementary Speech
In kindergarten and first grade, your child will continue to use more details in sentences as he starts conversations and answers questions. By the end of first grade, he should be able to give directions, answer who, what, where, when and why questions and retell stories in a logical order. At 7, he should be able to say all the sounds of our language, including l, s, r, v, z, ch, sh, and th.
Middle and Later Elementary Speech
Since all sounds have been mastered, speech growth at this age is more about communicating effectively. Around third grade, it should be easy for him to adjust his voice to the setting and to participate in conversations and group discussions. By fourth grade, a child should be able to make oral presentations and use language for a variety of purposes. He'll continue to expand his vocabulary and increase his ability to participate in both social and academic discussions, conversations and settings.