Both versions of the word are actually correct and widely used in the English-speaking world, but there is one small difference between the two words. 'Learned' is the preferred way of spelling in the US and Canada, while 'learnt' is favoured in British English.

Would have learned or would have Learnt?

Learnt and learned are both used as the past participle and past tense of the verb to learn. Learned is the generally accepted spelling in the United States and Canada, while the rest of the English-speaking world seems to prefer learnt.

How do you use learned and Learnt in a sentence?

Both are acceptable, but learned is often used in both British English and American English, while learnt is much more common in British English than in American English. We learned the news at about three o'clock. They learnt the train times by heart.