Receptive: Can't understand speech. Expressive: Can't produce speech (can't speak)

Persons with aphasia have trouble with expressive language, what is said, or receptive language, what is understood. Not only are speech and understanding speech affected, but also reading and writing is affected. The severity of aphasia varies.

The inability to speak can be termed aphasia or aphonia depending on the circumstances.

Damage to Broca's area causes an expressive aphasia, whereas damage to Wernicke's area causes a receptive (although illogcally sounding fluent) aphasia.

Though there is often an expressive aphasia (inability to speak, meaningfully), comprehension may be preserved. However, it the stroke victim is left with a receptive aphasia, there can occur the inability to comprehend.