This article is about the English word, 'because'. For the songs named "Because", see Because (Perry Como song) and Because (The Beatles song).

Because is a conjunction and adverb in the English language. In the loose interface between English and logic, it expresses various concepts of obligation and causality.

Because represents a reduced version of Middle English bi cause, "by cause". The phrase reason is because is frequently condemned by linguistic prescriptionists, on the grounds that because is thought to imply that a reason will be stated.

The hope of the usage commentators, that because requires a reason to be expressed, is not in fact born out in practice. "Because!" by itself, stated in a peremptory tone, is often thought to be sufficient reason in itself, especially among children or in the context of parenting. Because used in this manner represents an appeal to authority, or, more likely, the argumentum ad baculum.