Which of the following represents a use of an apostrophe?

The use of an apostrophe to show possession is a fundamental aspect of English grammar. When an apostrophe is placed before the letter "s" at the end of a noun, it signifies that the noun possesses something. For example, in phrases like "the cat's toy" or "Maria's book," the apostrophe indicates that the toy belongs to the cat and the book belongs to Maria. This usage clarifies relationships between nouns and their possessions, making sentences clearer and more precise.

Other options, while related to grammar, do not accurately describe the function of the apostrophe. The first choice incorrectly suggests that apostrophes separate names from verbs, which they do not do. The second choice inaccurately claims that apostrophes indicate plural forms; in fact, apostrophes are not used for forming plurals. Lastly, the fourth option presents an option that suggests apostrophes enhance adjectives, which is not a role the apostrophe plays in English grammar. Thus, the primary and correct function described is that of showing possession with the apostrophe's usage.