Communication Disorders: Types and Classification

By Joaquín Vidal López PhD

Teacher of the Master in Paediatric Speech and Language Therapy


Language disorder is characterised by the fact that individuals suffering it have difficulties persisting in time to learn and use normally the linguistic communication with others in all its modalities (oral, written, sign language, Braille system, etc.). Difficulties can be more important in producing or receiving language, although some individuals have problems in both processes.

Overall, people with language disorder have a reduced vocabulary (they know and use a small amount of words). They also do a limited use of grammar (sentence formation following the appropriate rules for each language). And finally, they have a poor or limited speech (they lack the ability to choose the suitable words and sentences to make themselves understood by others, which makes more difficult being able to follow a conversation).


man in the train
Communication disorders can affect how a person receives, 
sends, processes, and understands concepts

If language is assessed with a suitable valuation scale, scorings will be lower than expected for the individual’s age. These scarcities cause not only communication problems, but also poor academic performance, problems to set up social relationships or difficulties to find a job.

The beginning of these problems is used to be in the first stages of the development and they are not caused by either any auditory or sensory problems of any kind, motor disorders, or other intellectual problems (such as intellectual disability or global development delay).

On the other hand, the phonological disorder is characterised by the fact that individuals have difficulties to distinguish and articulate the phonemes which make their speech unintelligible for others and, in consequence, their oral communication is severely affected. As in the language disorder, individuals will have poor academic performance, problems to set up social relationships or difficulties to find a job. These difficulties appear at the early stages of the development and such problem is not caused by other difficulties such as cerebral palsy, cleft palate, hearing loss, etc.

In the case of childhood fluency disorders or cluttering, patients show alterations in the productions of fluently oral messages which appear as syllable, sounds or monosyllable repetitions, prolongations of some consonants or vowels, pauses in the middle of words, pauses in the speech (which can be full of other sounds or empty), the use of circumlocution to avoid saying words that cause difficulties, and verbalisation of words causing an excessive physical strain.



Cluttering causes anxiety in people suffering it and the same academic, labour and social problems than phonological and language disorders. Its onset is also given in the early stages of development and it is not caused by a known physical or psychical defect (motor disorder, brain tumour, sensory disorder, etc.).

Regarding the social (pragmatic) communication disorder, individuals have problems to keep a suitable verbal or non-verbal conversation from a social point of view. These individuals have difficulties to greet, sharing the appropriate information to the social environment, or to change the register when the environment changes (for instance, it is not the same speaking to a child than speaking to an adult, nor speaking to your colleague or an unknown individual). Therefore, they are not capable of changing from a formal register to a colloquial one, or to respect the speaking time in a conversation, or to understand the double meaning of some sentences, or to regulate the intonation or volume of their voice. As in the previous cases, the beginning age of this disorder is early and this difficulty will cause labour, academic and social problems.

In the classification of the specific speech and language disorders, the ICD-10 system makes a distribution of diagnostic categories which is shown in the following table.

Language disorder






Phonological disorder











Childhood fluency disorders or cluttering




Social (pragmatic) communication disorder

Expressive language disorder

o   Expressive developmental dysphasia or aphasia

Mixed receptive-expressive language disorder

o   Developmental Wernicke’s aphasia

o   Receptive developmental dysphasia or aphasia

Phonological disorder

o   Stammering

o   Dyslalia

o   Lalling

o   Phonological development disorder

o   Speech articulation developmental disorder

o   Speech articulation functional disorder

Other speech and language disorders

o   Childhood fluency disorder

1. Cluttering

2. Tachylalia

3. Stuttering

– Other speech or language development disorders

Language and speech development delay caused by a hearing loss.

Unspecified language and speech development disorders.


As we see in the previous table, in the ICD-10 classification, the language disorder can be classified as expressive language disorder and mixed receptive-expressive language disorder. In the first case, it would be a difficulty to communicate by both oral and written ways, although language understanding would be inside the normal limits.

Nevertheless, in the mixed receptive-expressive language disorder, the communication areas related with the reception and emission of language will be affected. Both disorders can vary from a mild to a severe level.

In the case of dysphasia, there will be a difficulty to make a proper use of language (both in its expressive aspect and in its receptive aspect), while in aphasia the incapacity will be total or almost total.

A particular case of aphasias is the developmental Wernicke’s aphasia in which individuals are unable to understand or repeat the oral language because they have damage in a zone of the temporal lobe (called Wernicke’s area) which is in charge of translating the auditory information coming to the ears in units of information. Many times, this aphasia appears in the adult age or in old ages as a consequence of a trauma or cerebral ischemia. In those cases it is called Wernicke’s aphasia. When it appears since birth and children are unable to acquire language with normality, it is called developmental Wernicke’s aphasia.

  • Among phonological disorders included in the ICD-10, there are the following:
  • Babbling: pronunciation of words or an ensemble of words in a unsteady or faltering way
  • Dyslalia: a speech defect caused by malformation of or imperfect distribution of nerves to the organs of articulation
  • This article is an extract from the module “Normal Development in Childhood and Adolescence”, part of the Master in Paediatric Speech and Language Therapy.



Master in Paediatric Speech and Language Therapy

Language Disorders: Assessment and Treatment in Childhood

Early Detection of Speech and Language Disorders