Here is an excerpt from an ASHA article on the topic:
"Although the stages that children pass through in the development of speech and language are very consistent, the exact age when they hit these milestones varies a lot. Factors such as the child's inborn ability to learn language, other skills the child is learning, the amount and kind of language the child hears, and how people respond to communication attempts can slow down or accelerate the speed of speech and language development. This makes it difficult to say with certainty where any young child's speech and language development will be in 3 months, or 1 year.
There are, however, certain factors that may increase the risk that a late-talking child in the 18- to 30-month-old age range, and with normal intelligence, will have continuing language problems. These factors include:
* Receptive language: Understanding language generally precedes expression and use. Some studies that have followed-up late-talking children in this age range have found, after a year, that age-appropriate receptive language discriminated late bloomers from children who had true language delays. Other researchers doing follow-up studies included only children whose receptive language was within normal limits because they believed that delay in this area was likely to produce worse outcomes.
* Use of gestures: One study has found that the number of gestures used by late-talking children with comparably low expressive language can indicate later language abilities. Children with a greater number of gestures used for different communication purposes are more likely to catch up with peers. Such a result is supported by findings that some older children who are taught non-verbal communication systems show a spontaneous increase in oral communication.
* Age of diagnosis: More than one study has indicated that the older the child at time of diagnosis, the less positive the outcome. Obviously, older children in a study have had a longer time to bloom than younger children but have not done so, indicating that the language delay may be more serious. Also, if a child is only developing slowly during an age range when other children are rapidly progressing (e.g. 24-30 months) that child will be falling farther behind.
* Progress in language development: Although a child may be slow in language development, he or she should still be doing new things with language at least every month. New words may be added. The same words may be used for different purposes. For example, "bottle" may one day mean "That is my bottle," the next, "I want my bottle," and the next week, "Where is my bottle? I don't see it." Words may be combined into longer utterances ("want bottle" "no bottle"), or such longer utterances may occur more often.
It should be re-emphasized that negative aspects of these factors increase the risk of a true language problem but do not mandate its presence. For example, one research group found that one of their 25- or 26-month-old children with the worst receptive language had the best expressive language outcome 10 months later. On the other hand, children on the positive side of these factors may turn out to show less progress than predicted. The research group found that the child with the poorest outcome had the best receptive language and the largest vocabulary at the beginning of the study.
One study has found that the number of gestures used by late-talking children with comparably low expressive language can indicate later language abilities."
So what should you do if you are concerned about your child's speech and language development?
Come see one of our speech-language pathologists, and we will answer any questions you have about your child's language development. Research has shown that the time between birth and 36 months is an extremely critical period of development, so our work in early intervention allows us to both identify and treat very young children in an effort to minimize any potential speech and language developmental issues.
Developmental Speech & Language Milestones, Birth - 5 Years of Age
Warning signs for communication disorder in young children