Which phrase best describes the main use of comparative form words?

The main use of comparative form words is indeed to compare two nouns. Comparative forms, often used in adjectives and adverbs, typically modify the comparison between two subjects, highlighting differences or similarities in qualities such as size, speed, or intensity. For example, when using the comparative form of the adjective "tall," one might say "John is taller than Mike," which directly compares the heights of the two individuals. This form clearly indicates a relationship between the two nouns, fostering a clearer understanding of how they relate to one another in terms of the described quality.

In contrast, the other options do not align with the primary function of comparative words: using phrases to emphasize a point relates more to persuasive language, introducing a new idea pertains to stating concepts rather than comparing, and presenting a contrasting argument focuses on opposing views rather than direct comparisons. These distinctions underscore the unique role of the comparative form in language.