Past tense of learn; the British English spelling (American English typically uses 'learned').
From Old English leornian and Old Saxon lornon. The -t ending is a regular past tense formation in Old English that survives in British English while American English shifted to -ed.
British and American English diverged on whether to say 'learnt' or 'learned' around the 1700s when America was developing its own standard, and both are technically correct, but Americans chose the newer -ed form while Britain kept the older -t.
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