The formation of the first two-word phrase is an important milestone in the speech and language development of a baby.
Babies understand more language than they can communicate. By nine months of age, they may have experimented with consonant sounds enough to acquire the words "Mama" and "Dada." It is unknown whether they understand what they are saying, but they are certainly rewarded by the response they get from Mom and Dad! They will probably not have any phrases in their own vocabulary yet, but should be able to respond to a simple phrase combined with a gesture, such as "Wave bye-bye." Parents often speak to young babies in a sing-song way, which research shows is helpful for the baby's language development.
The time between 12 months and 18 months is a critical time for language development. The first few words will probably be acquired during these months. Often, one of the first words after "Mama" and "Dada" is "cat" or "dog," if the child has been exposed to pets. Research indicates that many of the first words a child learns are words that a parent speaks in isolation. In other words, a parent may point to the cat and say "kitty." Speaking words in isolation, which is a very natural thing to do with a baby, encourages the baby to learn the word and try to say it.
Infants at this age will be able to express themselves nonverbally, as in reaching for what they want. They should be trying to imitate simple words. Some children enjoy imitating games and others seem to get frustrated by them. The main thing is that they are being exposed to language. To encourage vocabulary development, read board books together and ask the child to point to things in the pictures. Phrases may appear during this time, especially to label a person or an object, but it may be difficult to understand what the child is trying to say.
From 18 months to 2 years, language will continue to rapidly develop, with what some researchers call a "vocabulary spurt." The first two-word phrases will probably be heard during this time. The child will probably have a vocabulary of 8 to 10 words, but this will be expanding. Children, in their curiosity and desire to gain new words, often begin to use the two-word phrase, "Wassat?" or "What's that?" The first consonant sounds the child will pronounce correctly will probably be h, m, n, and p, with other sounds to follow. The child should be learning how to identify basic body parts and call favorite foods by name.
Two-word sentences should be heard by the second birthday. Many children will have them earlier. Since a two-year-old is basically self-centered, the first phrases to be heard are often "I want," "Me do," or "Give me." During this time, toddlers learn new words quickly, particularly those that refer to objects and actions. People close to the child will understand his or her speech better than a stranger. About 50% of what the child says may be understandable to an outsider. By age three, this should increase to 75%, and by four, they should be completely understandable.
While these milestones in the acquisition of phrases are averages, babies are individuals and can vary widely from these ages. Some children speak in complete sentences before their second birthday, and others don't utter a true word until after their second birthday. Frequent ear infections can cause a slower acquisition of language.
If your baby seems to be lagging behind, you may take her to a speech-language pathologist for evaluation. The pathologist will test the baby's hearing as well as evaluate her language development. This specialist may also recommend certain activities you can do at home to encourage speech development. These activities include reading books with your child and speaking to your child with simple words and short sentences that are easily imitated. Also, instead of constantly correcting your child when her pronunciation is wrong, try repeating it back correctly. An overemphasis on correct pronunciation can discourage a child from trying to speak.
Other factors that interfere with speech development are loud homes and pacifiers. When loud music or a television is always present, children cannot hear themselves experiment with sounds or try to say words. If a child sucks on a pacifier continuously, his or her speech is likely to be slow to develop and unclear.
