Aphasia can be receptive or expressive or mixed. It is an impairment, usually post stroke or traumatic brain injury, where someone has difficulty finding words or understanding the meaning of words. With expressive aphasia, they may have halting speech, long pauses, they may demonstrate substitutions, such as saying the wrong word which throws off the meaning of the sentences. With receptive aphasia, they may speak fluently but when listening to others they are unable to comprehend what they are saying, they need directions repeated, they may have trouble reading emails and making appointments.