Complete the sentence with the correct form of the verb in brackets: "By the end of the term the class had ____ (learn) two hundred new words."

Բացատրություն

Had calls for a past participle, and this verb offers two of them. The -t spelling is the traditional British one; the -ed spelling is usual in American English writing and is now just as common in British writing, so the past perfect works with either. What the slot cannot take is the base form, which carries no past meaning.