By Marcy Fox
With at least 8% of young children having speech or language disorders, you are likely to have students in your classroom who aren’t talking as much as they should, or who don’t sound quite right when they are talking.
Let’s take a look at typical development, starting with some basic definitions:
Language is what we are communicating. It includes words and what they mean, how words and sentences can be put together, and how we communicate with different people—in other words, vocabulary, grammar, pragmatics (how we know how to talk to others) and the rules that control these.
In simple terms, language can be divided into two basic categories:
Receptive Language (the understanding of language) and
Expressive Language (the use of language).
Speech is basically how we talk--that is, how we move our mouth, tongue, lips, teeth, etc. to make sounds (a.k.a. “articulation”), what our voice sounds like or the rhythm of our speech (a.k.a. “stuttering” or “fluency”).
While both speech and language are involved in communication, they are a little bit different.
Of course, all children do develop at their own pace, but we do have some general guidelines about how speech and language develops and what we expect children to be able to do.
Let’s look at a very brief overview of language and speech development:
Babies hear sounds and words in their environment and practice the sounds through babbling. Eventually, their first words come at approximately 12 months. Earliest developing speech sounds include /p, b, m, w, t, d, n and h/ and simple Consonant and Vowel syllables are the easiest. No wonder “mama” and “dada” are common first words!!
Around 18 months, most kids have spoken about 20 words and may be beginning to use simple 2 word sentences, like “want mama” or “go kitty.” Most of their words are nouns followed by verbs. Children are normally 25% intelligible (“understandable”) to their parents.
At 24 months, your student’s vocabulary should have exploded to about 200 words and he or she should consistently use 2 word sentences. Following simple directions (like “clap your hands” or “give me the ball”) as well as pointing to body parts should be pretty easy by now. Mom and dad should understand a 2 year old 50-75% of the time and strangers understand him or her 50% of the time.
At 3 years, your typically developing preschooler uses 900+ words and an average of 3-4 word sentences. He or she follow 2 step directions (“pick up the ball and throw it to Tommy” or “open the door and give me the pencil). Intelligibility typically is 75-100% but should be at least 50% to unfamiliar adults.
Your 4 year old student has a 1500+ word vocabulary and uses longer, more complex sentences, including telling stories and personal events. He or she is able to answer and ask many questions. This student should be fully intelligible to everyone, although not all sounds will be used correctly yet.
As your students turn 5 years old, their conversations become more adult-like and shouldn’t have too many grammatical errors. They should have most speech sounds, except for /s, l, r, th, ch, sh/.
More details
There really are a lot more details that a speech-language pathologist would look at to determine if your student had a speech or language disorder or delay and these are just general guidelines which, if a student is NOT doing, should cause concern. Although there is such a thing as a “Late Talker,” it is better to err on the side of caution and have them seen by a speech-language pathologist. Early intervention can help prevent future difficulties in reading and writing and overall academic performance.
Additional Resources
A little bit about Marcy Fox, M.A. CCC-SP
I've been a speech-language pathologist for about 11 years. I have worked in both a school and clinic setting with clients ranging in age from 2 all the way to middle school. Early intervention is my favorite, though! 
