The word ‘why’ is primarily used as an adverb in the English language. It is used to ask for the reason or purpose behind something. For example, in the sentence, ‘Why did you go to the store?’, ‘why’ is asking for the reason behind the action of going to the store.
In addition to being an adverb, ‘why’ can also function as a noun in certain contexts. When used as a noun, it refers to the reason or cause for something. For instance, in the sentence, ‘I don’t understand the why of his decision,’ ‘why’ is used as a noun to denote the reason behind the decision.
Understanding the part of speech of ‘why’ helps in constructing grammatically correct sentences and enhances overall communication skills.