Final answer:
A stroke affecting both Broca's and Wernicke's areas can lead to severe language impairments, with expressive aphasia affecting speech production and receptive aphasia impairing language comprehension.
Step-by-step explanation:
Damage to Broca's area and the supplementary speech zone typically results in forms of aphasia, which are language impairments following a stroke in these regions. Broca's aphasia, characterized by expressive aphasia, involves significant difficulties in speech production, leading to non-fluent, broken, and halting speech, often with compromised grammar. People with Wernicke's aphasia suffer from receptive aphasia, where language comprehension is affected, making it hard for them to understand spoken language or the meaning of their own words, even though they can speak fluently. Strokes affecting both areas can contribute to severe disruption in both language production and comprehension.