| Age |
Speech development norms |
| 2 months |
Isolated sounds and spontaneous vocalizations directed at the mother and sometimes at other adults. |
| 3 months |
Prolonged vowel sounds, cooing, and a response when spoken to. |
| 4 months |
Cooing develops into trills (one vowel flows into another); the baby responds to changes in intonation. |
| 5 months |
Melodic cooing and random babbling; some consonant sounds (p, b, m) are added, and the first syllable combinations appear. |
| 6 months |
Random babbling improves, consonants merge with vowels, and the baby tries to imitate sounds he or she hears. |
| 7 months |
Babbling and understanding of the meaning of words. |
| 8 months |
Babbling as a form of communication; imitation of sounds spoken by adults without understanding their meaning. |
| 9 months |
More complex babbling, sound "serenades," and the first simplified words. |
| 10 months |
Understanding of more and more words, imitation of adult speech, and new syllables and simple words appearing in speech. |
| 11 months |
Producing sounds at will and a growing number of simplified words. |
| 12 months |
Ease in imitating newly heard words, about 10 simplified words in active use, and understanding of more than 20 words. |
| 2nd year of life |
Autonomous active speech (use of amorphous root words); at 1.5 years, use of one word to refer to a range of objects; at 2 years, matching familiar words with pictures; by the third year, attempts to modify words; understanding and following the simplest commands. |
| 3rd year of life |
Connected speech, sentences that appear and gradually become more complex, the first questions, changes in intonation, rapid vocabulary growth, and creating new words. |
| 4th year of life |
Sentences made up of a subject, predicate and object; correct pronunciation of most sounds; the ability to answer the simplest questions; and use of phrases of more than four words. |