The problems children face in their lexical and phonological development.

   
 During the early years development of a child's language, they have difficulty with the lexical framework. For example, having a limited vocabulary, not using synonyms for other words, that have the same meanings. Also, antonyms which are words that have opposite meanings. It derives from the Greek words "anti" for opposite and "onym" for name. Young children, in the early stages of learning the English language, do not associate words with other words. For example, they do not group words together like 'salt' and 'pepper' or 'black' and 'white'. These word groups are called 'collocations'. They also have difficulty with choosing to use words that convey a particular register (informal or formal). This is because they have difficulty sculpting their vocabulary in order to be cohesive with the setting or audience etc. 

As a child's vocabulary advances and expands, they have to learn how to distinguish different sounds and to segment the speech stream they hear, into phonemes. The phonemes /units of words, when written are made clear by leaving spaces between each word. However, in spoken language, words are spoken in a successive stream without clear pauses. Making it therefore difficult for a child to differentiate between words and to know when one word ends and another begins, e.g. 'a cup of coffee' when spoken, is 'acupofcoffee', if not familiar with the English language, it is difficult to know if 'a cup' are two individual word units or if 'cupofc', is a single unit.