Which aspect of language is assessed by asking a participant to explain a proverb?

Asking a participant to explain a proverb primarily assesses their understanding of figurative language. Proverbs often convey meanings that go beyond their literal interpretations, using metaphorical expressions that reflect cultural insights or moral lessons. By explaining a proverb, the participant must demonstrate their ability to interpret these underlying meanings, recognize the figurative expressions, and connect them to broader themes or concepts. This engagement with figurative language is crucial for effective communication and comprehension in more complex and nuanced contexts.

The other choices, while important components of language, do not specifically target the nuances involved in interpreting proverbs. For instance, constructing sentences, following grammar rules, and using synonyms focus more on structural aspects of language rather than the understanding of deeper meanings conveyed through figurative language.