The word ‘hard’ can function as different parts of speech depending on its usage in a sentence.
As an adjective, ‘hard’ describes a quality, such as in the sentence: She has a hard exterior. In this case, it conveys that the exterior is not soft.
Additionally, ‘hard’ can be used as an adverb, especially when describing the intensity of an action, as in: He worked hard to finish the project. Here, it emphasizes the manner in which he worked.
In summary, ‘hard’ is primarily used as an adjective or an adverb, showcasing its versatility in the English language.