Complete the sentence with the correct form of the verb in brackets: "The ladder had ____ (lean) against the wall all winter."

Explication

A past participle follows had, and this verb fills that slot in two ways. The -ed spelling is now the more common one in British as well as American English writing, while the -t spelling keeps its place in more traditional British prose; the difference is regional and stylistic, not grammatical. Only the base form would be wrong after had.