Phonological development in Children

Children at a young age tend to make simple and abstract errors when stepping up and speaking to an adult as they are learning to speak just like them, these are known as phonological processes, here is an example of some:

Phonological Process Example   Description   Pre-vocalic voicing car = gar A voiceless sound preceding a vowel is replaced by a voiced sound. Word final devoicing red = ret A final voiced consonant is replaced by a voiceless consonant Final consonant deletion boat = bo A final consonant is omitted (deleted) from a word. Velar fronting car = tar A back sound is replaced by a front sound. Palatal fronting ship = sip sh or zh are replaced b y s or z respectively Consonant harmony cup = pup The pronunciation of a word is influenced by one of the sounds it 'should' contain. Weak syllable deletion telephone = teffone Weak (unstressed) syllables are deleted from words of more than one syllable. Cluster reduction try = ty A cluster element is deleted or replaced. Gliding of liquids ladder = wadder Liquids are replaced by glides. Stopping ship = tip A stop consonant replaces a fricative or affricate.

If a child finds difficulties pronouncing a word liker an adult, then Phonetic Simplification may take place, one form of this is known as deletion, this is where the child will discard either the first or the last consonant, for example "spor" or "port" instead of sport.  Another form of Phonetic Simplification is substitution, this is where if a child cannot pronounce a particular consonant, then they will simply replace it with a consonant they can pronounce for example "dun" instead of "sun".

There are several sounds children can say relatively quickly and are able to use almost immediately, these include: vowels, p, m, h, t, w, n, b and t. The more difficult ones include k, g, f, v, y, r, i, s ,ch ,ng and sh

http://www.talkingkids.org/2011/04/speech-sounds-and-kids-part-2.html

https://cogsci.uni-osnabrueck.de/~CL/download/BachTh_TobiasRauch.pdf

http://www.speech-language-therapy.com/index.php?option=com_content&view=article&id=30:table2&catid=11:admin&Itemid=117