In American English, learned is the past-tense form of the verb to learn. Learnt is sometimes used for this purpose in other varieties of English, though learned is the more common form everywhere.
Writers throughout the English-speaking world use learned as the adjective meaning possessing broad, profound knowledge. And, incidentally, this sense of learned is pronounced with two syllables—”lur-ned.” As a verb, learned is usually one syllable.
Examples
Here are a few examples of learnt used in British publications:
What’s more, I learnt that it is possible for scientists to influence these enquiries … [Guardian]
But, just like Peter Siddle, he has learnt tricks from other sports … [Telegraph]
As a result of both, I have learnt a number of lessons (some of them the hard way). [Financial Times]
The same publications use learned much of the time, however.
American publications prefer learned:
He learned to read at a little schoolhouse where his parents had gone as well. [NY Times]
Here is what we learned: We learned that golf with a struggling Tiger Woods is pretty nondescript. [WSJ]
As I learned over the next few days, when it comes to cocktail culture, the entire state of Utah is kicking it up a notch … [Washington Post]
Ngram
This Ngram visually renders the use of learned and learnt in American books published from 1800 to 2000.
And this one shows the words’ use in British books from the same period:
Keep in mind, though, that both these Ngrams are skewed, even if only a little, by the adjectival learned.
