because

This conjunction establishes a direct causal link between an effect and its cause. It is neutral in register and appropriate for both formal writing and casual speech. While it is the most common way to express reason, it is often replaced by "since" or "as" in formal contexts when the reason is already known to the listener.

Users must distinguish between "because" and "because of." The former introduces a full clause containing a subject and a verb, whereas the latter functions as a prepositional phrase followed by a noun or pronoun. Using "because" followed by a noun phrase is a common grammatical error in standard English.