Speech sound development varies greatly between boys and girls as well as between ages. Below are two charts that provide information about age of acquisition of speech sounds. Speech Pathologists have researched the age of acquisition of consonant sounds in Standard American English for many decades. Each study found slightly different results regarding the age of mastery. I have provided the norms listed from the Goldman Fristoe Test of Articulation, 2nd Edition (GFTA-2). The GFTA-2 has been a widely-used articulation assessment for over 30 years. The age of mastery was determined by 85% of the sample population having the target sound mastered in the initial, medial, and final position of words. You can view a chart below with each sound and the typical age of mastery.
These charts should be used as a reference, not as a definitive means of determining if speech services are warranted. If your child is difficult to understand or is experiencing challenges with pronunciation of sounds, please contact a licensed speech language pathologist for a full evaluation.'