It can be difficult to tell whether a child is just immature in his or her ability to communicate or has a problem that requires professional attention. These developmental norms may assist you in knowing what's "normal" and what's not in speech and language development can help you figure out if you should be concerned or if your child is right on schedule. :
Before 12 Months
Cooing and babbling are early stages of speech development. As babies get older (often around 9 months), they begin to string sounds together, incorporate the different tones of speech, and say words like "mama" and "dada" (without really understanding what those words mean). Before 12 months of age, babies should also be attentive to sound and begin to recognize names of common objects (bottle, binky, etc.). Babies who watch intently but don't react to sound may be showing signs of hearing loss.
By 12 to 15 Months
Kids this age should have a wide range of speech sounds in their babbling (like p, b, m, d, or n), begin to try and imitate sounds and words used by family members, and typically say one or more words (not including "mama" and "dada") spontaneously. Nouns usually come first, like "baby" and "ball." Your child should also be able to understand and follow simple one-step directions ("Please give me the toy," etc.).
From 18 to 24 Months
Though there is a lot of variability, most toddlers are saying about 20 words by 18 months and 50 or more words by the time they turn 2. By age 2, kids are starting to combine two words to make simple sentences, such as "baby crying" or "Daddy big." A 2-year-old should be able to identify common objects (in person and in pictures), points to eyes, ears, or nose when asked, and follow two-step commands ("Please pick up the toy and give it to me," for example).
From 2 to 3 Years
Parents often see huge gains in their child's speech. Your toddler's vocabulary should increase (to too many words to count) and he or she should routinely combine three or more words into sentences. Comprehension also should increase — by 3 years of age, a child should begin to understand what it means to "put it on the table" or "put it under the bed." Your child also should begin to identify colors and comprehend descriptive concepts (big versus little, for example).