Final answer:
Taking the comma out of the sentence 'Let's eat, Grandma' changes the meaning substantially because it alters the punctuation needed to indicate direct address.
Step-by-step explanation:
Taking the comma out of the sentence 'Let's eat, Grandma' changes the meaning substantially because it alters the punctuation needed to indicate direct address. When the comma is removed, the sentence becomes 'Let's eat Grandma,' which can be interpreted as an invitation to consume Grandma as food, rather than an invitation for Grandma to join in eating. The comma in the original sentence is crucial to convey the correct meaning and avoid ambiguity.
Learn more about the importance of punctuation in conveying meaning