USA HISTORY

Detailed explanation-1: -Learnt and learned are two different spellings of the past tense of the verb ‘learn’, which means ‘gain knowledge or skill’ or ‘come to be able to do something’. The spelling tends to vary based on the version of English: In UK English, ‘learnt’ is standard. In US English, ‘learned’ is more common.

Detailed explanation-2: -Merriam-Webster defines learning as “gaining knowledge or understanding of or skill in by study, instruction, or experience.” You’ve learned something if you can answer a question that you could not have answered previously.

Detailed explanation-3: -They both sound odd out of context, because learn usually has an object: “Did you learn anything today?” and “Have you learned anything today?” are both correct. When learn doesn’t have a direct object, it usually has an adverb with it, such as “Your son is very clever-he learns quickly."

Detailed explanation-4: -It depends on context. Either can be grammatically correct. If the powerpoint presentation is a summary of your first year at your current job, “What I’ve learned” might be more appropriated. If you are recounting a conference you went to two months ago, “What I Learned” could be the better choice.