Children's language skills develop rapidly in the first three years of life. Most babies progress from incoherent babbling to speaking fully formed, multiple-word sentences during that time. Though different children develop at slightly different rates, most children hit certain linguistic milestones by age 3.
Response to Speech
By 6 months old, most babies respond to their own name. At this age, babies will also respond to voices by turning their head and eyes to look for the source of the sound. Six-month-old babies can typically differentiate between friendly and angry tones of voice, and can respond accordingly. By 12 months, babies can understand simple instructions given with visual cues. By 18 months, most children can follow simple commands, and by 24 months old, they can respond to specific instructions such as "Point to your nose!" By the time most children reach the age of 3, they can understand basic questions having to do with their surroundings, activities and feelings.
Speech
From birth to 6 months, most babies vocalize without meaning or intonation. By 12 months, most babies begin to use one or more words or word fragments with clear meaning. Children at this age begin to absorb the words used around them at home, the PBS Parents website explains. Babies also begin to practice intonation and inflection at this age. Most children's voices and pitch remain relatively uncontrolled even at 24 months, though most of their speech should be coherent, the Child Development Institute notes. Most 24-month-olds often have an inconsistent rhythm of speech. By 3 years old, children's speech should be 90% coherent, the institute adds.
Vocabulary
Most babies say their first words by 12 months, according to the Child Development Institute. By 18 months, most babies have developed a vocabulary of five to 20 words, mostly nouns. Children at this age might repeat single words over and over. By 24 months, children can typically name many of the objects that surround them at home. At this age, a child's vocabulary expands every day. The average 24-month-old has a vocabulary of 150 to 300 words. By age 3, children typically have a vocabulary of 900 to 1,000 words, and can name the parts of the body as well as identifying facts about themselves, such as their gender, age and name.
Grammar
By 24 months, children can typically use a few prepositions, such as "in" and "on." At this age, children begin to put together two-word sentences using a noun and a verb. Most children also begin to use the pronouns I, me and you at this age, and some use the possessive pronouns me and mine. By age 3, children use more prepositions and pronouns and begin to put together three-word sentences, sometimes using plural and past tenses. By this age, children often initiate conversations, eager to describe their experiences or tell stories.
Literacy
One-year-olds enjoy looking at illustrated books and hearing nursery rhymes. Children beginning to build their vocabularies at this age might point at and name different items in picture books, according to PBS Parents. By age 2, many children pretend to read by flipping through familiar books. Though many 2-year-olds can sing the alphabet song, most do not yet understand the connection between the sounds of the letters and their written symbols. Children at this age might scribble in an attempt to write letters. By age 3, most children understand that a book's text prompts the reader to say certain words, PBS Parents adds.
