Clinical linguistics studies language and communication impairments, focusing on the linguistic aspects of communication disorders to aid in assessment and treatment. It distinguishes itself from fields like neurolinguistics by emphasizing linguistic features over underlying causes of disorders. The field evolved significantly from the 1920s through the 1980s, notably through contributions by scholars like Jakobson and Crystal, who helped establish it as a recognized subdiscipline of linguistics.

1. Applied Linguistics
Clinical Linguistics

2. Definition & Focus
 Clinical linguistics: The study of how language and
communication may be impaired
 Focus  The use of linguistics to describe, analyze, assess,
diagnose and treat communication disorders
 It is commonly taken to include the study of clinical language
data in order to throw light on the nature, development and use
of normal language and thus to contribute to linguistic theory

3. Scope
 No level of language, from phonetics to discourse, is
immune to impairment, with problems manifested in both
the production and comprehension of spoken, written and
signed language across the human lifespan.

4. ‘Behavioral’ VS. 'Medical’ model
of language pathology
 The fact that communication disorders may be manifested
linguistically does not necessarily mean that they will
always have a specifically linguistic cause.
 It is still possible to characterize the linguistic features of
any speech disorder precisely enough to be able to design
assessments and remedial programs even though one does
not know the cause of the deficit.
 This key grounding in which distinguishes clinical
linguistics from related fields such as neurolinguistics and
speech and language pathology, which accord primary
importance to the underlying causes of communication
disorders.

5. History of Clinical Linguistics
1. 1920s: a particular variety of lisping were still treated by
a neurosis.
2. Jakobson 1941: Child Language, Aphasia and Phonological
Universals was a major milestone in putting the study and
treatment of communication disorders on a more
scientific footing, based on the discipline of linguistics
which emphasized the importance of studying systematic
patterns of similarity and contrast in clinical language
data, and relating these to linguistic theory. The
assumption that atypical speech or language, however
deviant, must still be systematic and rule-driven.

6. 3. David Crystal 1970s and 1980s: he set up the first degree
course in Linguistics and Language Pathology at Reading
University in 1976.
4. publication of Clinical Linguistics (Crystal 1981):
consolidated and defined the field. Crystal’s book had
the effect of according the term “Clinical linguistics” an
official status, as it were, with the result that clinical
linguistics came to be more and more widely accepted as
a distinct subdiscipline of linguistics.