Photo Articulation Test, 1969, Pendergast et al, and Stoel-Gammon, 1985. Child produces 3 to 6 different speech development of children of younger preschool age sounds with each child having a little different consonant inventory. Produces Most Vowel Sounds Correctly and at least 6-8 different consonant sounds. Child uses at least 9-12 different consonant sounds.
Most children have mastered nearly all vowel sounds by age 2. By 2 a child should use at least 3 to 4 different consonant sounds at the beginnings of words. By 3 a child should have a large repertoire of initial consonants. This is atypical phonological development and should be targeted even in very young children. By 24 months in language delayed children some final consonant deletions are expected, but by 36 months, all children should be producing words with ending consonant sounds. Again there is variation in individual children, but for the most part, parents should understand close to all of what a child says by age 3, and strangers should understand all of what a child says by age 4, even if errors are still present.
I also want to share with you a FANTASTIC quick resource for practically all Communication Milestones in young children from Linguisystems. It’s evidence based and a it’s FREE download. I use my hard copy all the time! My daughter just turned 3 on 10-2-09 and has been exposed to three different languages. Her speech in English is unclear at times.