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Speech Developmental Milestones

Lists of age of acquisition for sounds in speech and common phonological processes are listed below: 
Sanders ( 1972) Norms for Speech Sound Mastery
(Concerns arise when the child passes the age of acquisition and cannot produce the sound
or has numerous errors making speech less than 50% understandable in conversation)
Age 3: p, m, w, n, h
Age 4: b, d, k, g, y (as in yes), f
Age 6: t, l, r, ng
Age 7: j (as in jump), ch, sh, th (unvoiced as in think)
Age 8:  v, th (voiced as in the) s, z
            (zh is mastered later than 8)
Common Phonological Processes (Should not persist beyond age 5):
Final consonant deletion:                   says “ba” instead of “ball”
Syllable reduction:                             says “nana” instead of “banana”
Vowelization:                                     says “ca” instead of “car”, “penso” instead of “pencil”
Gliding:                                              says “wed” instead of “red”, says “syide” instead of “slide”
Cluster Reduction:                              says “boom” instead of “broom”
Doubling:                                           says “ho-ho” for “horse”, says “wa-wa” instead of “water”
Initial Consonant Deletion                   says “all” instead of “ball”
Backing (not a common process):         says “gog” instead of “dog”
Fronting:                                           says “tat” instead of “cat”
Glottal Replacement:                          say “ba-tub” for “bathtub”