One-year-olds are building a foundation for language. They absorb the language around them and are steadily building their vocabularies. They understand common phrases and simple directions used in routine situations. They have great difficulty with pronunciation, and familiar adults almost always need to "translate" for others. During this year, communication skills typically progress from grunting and pointing to speaking single words and experimenting with simple word combinations.
At 12 months, understands 50 words; at 15 months, 120 words; at 16 months, 170 words; at 18 months, 200 or more words.
Between 12 and 15 months, acquires about one word every other day. During a "spurt" between 16 and 23 months, children typically acquire one or two words per day.
At 12-14 months, learns words when adults name objects that are nearby or in hand. By 14 or 15 months, points to objects further away for adults to name.
Vocabulary words include many nouns (names of things), some verbs (e.g., kiss, kick, open, sleep), some descriptive words (e.g., cold, full, all gone, broken), some pronouns (e.g., he, me, mine) and some location words (e.g., down, in).
Understands a few common phrases used in routine situations (e.g., "Do you want more?", "Give me a kiss.", "Let's go bye-bye.").
Understands simple directions used in routine situations (e.g., "Stop that.", "Spit it out.", "Please hold still.", "Sit down.", "Stand up.")
Understands only the simplest explanations in routine contexts.
Perceives individual speech sounds in native language. Is less able now than at 6 months of age to discriminate individual sounds in other languages, and this sensitivity will continue to decrease.
Distinguishes between commenting and questioning intonation (patterns of pitch changes in speech), and between a positive and negative tone of voice.
At 12 months, the average child says up to three words and may also communicate by grunting, nodding, pointing, etc. At 15 months, the average child says 14 words. At 16 months, the average child says 40 words. At 18 months, the average child says 68 words. At 23 months, the average child says about 200 words.
Over- and under- extends meanings. For example, a child calls a cow "horsie" or does not use "shoe" to label footwear that is not a common shoe (i.e., boot or sandal).
From 12 months to 24 months, words are rarely spoken correctly in the adult manner. Has great difficulty with pronunciation. Parents and caregivers almost always need to "translate" for others
Up to about 18 months, children express themselves with single words, using different vocal sound changes to show what they mean. Around 18 months, children typically experiment with combining words to form phrases and sentences. Such communications consist of a few words, and are lacking parts of speech (e.g., "Mommy sock?" for "Is this Mommy's sock?", "Daddy go." for "Daddy is going bye-bye.").