List of Skills by Age

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1-2 Months

No observable sound errors

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2-4 Months

No observable sound errors

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4-6 Months

No observable sound errors

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6-8 Months

No observable sound errors

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8-10 Months

No observable sound errors

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10-12 Months

No observable sound errors

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12-15 Months

Often repeats same syllable (“wawa” for water)

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15-18 Months

Reduces consonants (“boo” for “blue”)

Final consonant deletion evident (“be” for “bed”)

Eliminates some initial consonants

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18-21 Months

Additional research needed

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21-24 Months

Additional research needed

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24-27 Months

Additional research needed

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27-30 Months

May delete one consonant from a consonant blend (e.g., top/stop)

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30-33 Months

Cluster reduction, cluster of sounds reduced (e.g., peak/speak)

Gliding may occur (substitution of glide /w/ or /y/ for liquid sounds, /r/ or /l/ (e.g., woom/room)

Stopping /th/ (e.g., dis/this)

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33-36 Months

Simplifies words that are multisyllabic to CV or CVCV form (e.g., banana becomes "nana")

Produces substitutions and distortions of consonants

No longer substitutes a voiced consonant for an unvoiced consonant (e.g., zun/sun)

Substitutes /f/ for voiceless /th/ (e.g., fumb/thumb)

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36-42 Months

May use stopping, or substituting a stop /b, p, d, t, g, k/ for a fricative /s, z, f, v, th, h, sh, zh/ (e.g., moud/mouse)

May use fronting, produce a consonant in the front of the mouth that should be produced in the back (tar/car)

May use cluster reduction (tuck/truck)

75% of children: No longer delete final consonants (e.g., ba/ball)

75% of children: No longer change one sound or syllable in the word to be like another (e.g., goggie/doggie)

75% of children: No longer repeat syllables (e.g., baba/bottle)

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42-48 Months

75% of children: No longer substitute a front sound for a back sound (e.g., tat/cat)

75% of children: No longer replace an affricative with a continuant or stop (e.g., sip/chip)

75% of children: No longer reduce consonant clusters (e.g., gape/grape)

75% of children: No longer deletes unstressed syllables

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48-54 Months

75% of children: No longer substitute non-palatal sounds for palatal (tongue on palate) sound at the end of a word (e.g., dit/dish)

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54-60 Months

75% of children: No longer substitute non-palatal sounds for palatal (tongue on palate) sound at the beginning of a word (e.g., tai/shy)

75% of children: No longer substitute alveolar (made with tongue near upper teeth ridge) for non-alveolar (e.g., tu/shoe)

75% of children: No longer substitute voiceless final consonant for a voiced consonant (e.g., bak/bag)

75% of children: No longer omit /s/ in an initial position of a cluster (e.g., tep/step)