usually phonoligcal developments depends on the individual. children usually lean vowels and consonants at different speedss. some phonemes are learnt alot earlier such as vowels. Most children will be able to use all the vowels in English by the time they're two and a half years old.
However they may not use most of teh consonants confiently until they're are around six or seven. earlier consonats they they master in speaking are usually around the nasals "m", "n" sounds and voiceless plosives /p/, /k/ and /t/. the last ones tend to be the /th/ sounds or fricatives. usually children find it easier to the consonants at the beginning of the words such as /b/ the word /b/ook rather than b /in/ the words cur/b/.
simplifiations usually helps childrent o communicate, children if they have trouble communiating with certain words they may use phonological simplification i.e. deletion, where the child may drop a consonantat the end of a wordsuch as they may say say /ca/ rather than cat. substition is where instead of dropping a consant a child may replace it with what is easier to say. cluster reduction where there are two consonants together in line in a word and the child may drop pne of them.
other features that sre common in phonoloical development is addition, assimilation, reduplication, voicing and devoicing. all of these features are very…