Speech sounds in English Language

As we develop we are able to produce and learn to coordinate different speech sounds.  The speech sounds are divided into early developing sounds, early elementary sounds and later developing sounds. In general, all five year old children will produce each of the sounds listed below 50% of the time correctly. By the time a child has turned 8 they should have mastered all of the speech sounds and should be at least 90% intelligible to an unfamiliar listener.

The early developing sounds are p, b, m, h and w.  
The early elementary sounds are k, g, f,v, t, d and n.  
The later developing sounds are s, z, sh, ch, j, l, th, ing,  and r.
              
According to Sander JSHD 1972; Smit, et al JSHD 1990.  

Signs of a Speech Sound Disorder

• Says p, b, m, h, and w incorrectly in words (1–2 years)
• Says k, g, f, t, d, and n incorrectly in words (2–3 years)
• Produces speech that is unclear, even to familiar people (2–3 years)