Definition: Demonstratives are words or phrases that serve as examples, comparisons, or definitions for more specific or abstract concepts. In formal language, a demonstrative refers to a word that gives an example or context for a more complex concept or idea. For instance: - 'The sun is bright' - This sentence uses the demonstrative 'is' to indicate something about the sun. The sentence introduces a new concept of brightness by using a specific and concrete example (the sun) of what the concept might be. - 'She was very upset' - This sentence uses the demonstrative 'was' to introduce an action or feeling that is being described. The sentence introduces a new concept of emotional state (shocked or upset) through a more abstract comparison. Demonstratives are essential in formal language because they allow speakers to create specific, concrete examples and definitions for complex concepts or ideas without having to rely on vague or general statements.