Final answer:
Broca's area, located in the frontal lobe of the left hemisphere, is key for planning articulation and constructing grammatical sentences; it is integral to speech production and language function.
Step-by-step explanation:
The area of the brain responsible for the planning of articulation and generating grammatical sentences, especially in the left hemisphere, is known as Broca's area. This region is situated in the frontal lobe and is associated with the motor commands necessary for speech production. Approximately 95 percent of the population predominantly uses the left hemisphere for language production, making it the linguistic hemisphere. The functions of Broca's area are contrasted with Wernicke's area, which is involved in language comprehension. While Broca's area is linked to expressive aphasia, where speech production is compromised, Wernicke's area is associated with receptive aphasia, affecting the understanding of language.