Can you end a sentence with a preposition?

The rule has no basis in how English works. It appears to originate with John Dryden in 1672, who criticized ending clauses with prepositions largely because Latin grammar does not permit it, and it was propagated by 18th-century prescriptivists applying Latin structure to a Germanic language that never followed it. English has used stranded prepositions since Old English, including in the King James Bible and throughout Shakespeare. Merriam-Webster, the Chicago Manual of Style, Fowler, and Garner all reject the prohibition explicitly.

The practical argument is stronger than the historical one: obeying the rule frequently produces stilted sentences. What did you step on becomes on what did you step, which no one says. The apocryphal Churchill line about arrant pedantry up with which he would not put makes the point even though the attribution is dubious. Two genuine cautions survive. Avoid the truly unnecessary trailing preposition, as in where are you at, where at adds nothing to where are you. And in the most formal registers, a reader who believes the rule may judge you for breaking it, which is a social calculation rather than a grammatical one. Fronting the preposition is a legitimate stylistic choice when it reads well and a mistake when it does not.