English grammar forbids beginning sentences with the conjunctions 'and' or 'but.'
This rule is a prescriptive invention with no basis in English grammar or syntax. Sentence-initial conjunctions have been used in published English literature since Old English texts and appear throughout the King James Bible, Dickens, and contemporary literature. Modern linguists and major style guides (Chicago Manual of Style, AP Stylebook) explicitly permit initial conjunctions as stylistically effective devices. The misconception likely originated in schoolroom writing instruction attempting to prevent dependent fragments ('And then we went home' as a sentence fragment), but the rule was over-generalized. Coordinate conjunctions at sentence start are grammatically sound and often rhetorically powerful for emphasis and rhythm.