Affixes

Psychologists use these terms for speech disorders that are mainly caused by brain damage. Examples are aphasia (Greek a‑, not), inability, or impaired ability, to understand or produce speech; dysphasia (Greek dus‑, difficult), deficiency in the generation of speech, and sometimes also in its comprehension; paraphasia (Greek para, amiss, irregular), jumbling of words and production of meaningless sentences.

Associated adjectives are formed in ‑phasic: aphasic, dysphasic. However, some in that ending derive instead from nouns ending in ‑phase, for example biphasic, having two phases, or polyphasic, consisting of or occurring in a number of separate stages.