This is component of the evaluation process is very important as it looks at our ability to communicate with our fellow humans. Multiple aspects of speech and language are examined including: 1) articulation; 2) expressive language; 3) receptive language; 4) phonological processing; and 5) written language (i.e., reading & writing).
Phonological processing and written language have been discussed elsewhere. Articulation refers to the ability to accurately pronounce words. For example, many individuals with language-based deficits tend to mispronounce words (e.g., “ax” instead of “ask”) or they may have a lisp, slur words, stutter or be unable to effectively pronounce certain letter combinations (e.g., th may be pronounced as f; teeth–>teef).
Receptive language refers to our ability to understand language, including the ability to follow directions and respond to questions asked. For example, many children with autism spectrum disorders have difficulty following complex directions, partly because their comprehension is limited. When you tell them, “Give me the book.” the follow with little difficulty. On the other hand, when you tell them, “Give me the third book on the left.” this becomes too complicated as they have to consider book number three from a particular direction.
Expressive language is the ability to communicate our thoughts to others in a manner that is coherent. It requires the person to have proper knowledge of grammar (although this knowledge can be implicit) and a vocabulary that is sufficiently diverse so as to be able to convey content. When this aspect of language is limited, the person has a hard time stating what is on his or her mind, leading to frustration, anger, and possibly acting out as a way of expressing their internal state.
Each of these components of speech and language is evaluated due to the fact that deficits in each can lead to decreased performance on other measures of cognitive ability as well as significant problems with academics, work and social relationships.
Of special note, some children with delays in language/speech development will have difficulty when required to learn a foreign language. Specialized testing is available to assess the child’s abilities in this domain.