Pretty sure that it's more correctly 'I would like to review all that I've learned'. And just for fun, here's a another variant. I would like to review that which I've learned.
In the USA we're more likely to shorten it to: "review what I learned."
"Learnt" is indeed more common in the home of the English language as opposed to our former colonies.
I doubt that you'll hear anyone say "learnt" in the USA, although we all understand it.
However, we retain "learned" as a
two-syllable word for "educated," as in "a learned man."
It's just one of a number of irregular verbs, and I'm sure you haven't removed all of them from your version of our language.
Oh heavens no. In fact we've added more. Americans have long used "snuck" as the past tense of "sneak." Originally it was Hillbilly dialect, but it's spread out into the general population.
Lately "dove" (with a long O) has been pressed into service as the past tense of "dive," on the model of strive/strove, drive/drove. Fortunately no one has yet invented "diven" as the past participle.
Do you still say "knelt" or do you always use "kneeled"?
Learned people

might say that, but
the hoi polloi (an atrocity since
hoi is, literally, "the," so the expression translates to "the the people") rarely do.
Spoil, dream, leap, lean, keep etc... and learn is just another of those wonderful things.
The only one of those in universal use on this side of the Whaleroad is "kept." No one says "keeped," not even in AAVE (African-American Vernacular English or "Ebonics").
Nobody says "leant" because it sounds like "lent," the past tense of "loan." And yes, Americans are more likely to say "loaned."
No one flinches if they hear or read "spoilt" and "dreamt," but you'll probably never
hear or read it in American dialect except when an old poem is being recited.
It's interesting that these are all
weak verbs--verbs that only have two forms: present and past. Most irregular verbs are
strong verbs, with three forms for present, past and past participle, e.g., sing/sang/sung. The inflection is in
umlauting the vowel rather than adding a suffix.
But dream/dreamt and leap/lept have only two forms and they retain the "-ed" which is the inflection for weak verbs in the past tense, although it's changed from -D to -T.
As Oscar Wilde wrote in "The Canterville Ghost" back in 1887: "We have really everything in common with America nowadays, except, of course, language."
Someone else said that the U.K. and the U.S.A. are "two peoples divided by a common language."
In the USA, regional dialects have virtually disappeared, and even regional accents are being leveled, due to two phenomena:
- Radio and television. The synthetic Hollywood/Manhattan accent (from the country's two major broadcast centers) is heard in every home and children pick it up.
- Mobility. These days the average American changes jobs every five years and this often results in moving to another part of the country. If you live in a city of any size, every day you'll hear the accents of all the major regions of the USA--not to mention Chinese, Korean, Vietnamese, Indian, Russian, Latin American, Arabic and diverse African tongues.
Communication technology is even leveling the difference between American and British English. We've been listening to each other's rock'n'roll and watching each other's movies and TV shows for decades now, so we've adopted much of each other's slang. As I understand it, you guys no longer say "knock you up" meaning "come to your home and take you somewhere" since in American slang it means "get you pregnant."
We both know that what you call a "bird" is what we call a "chick"--which is actually of Spanish origin:
chica, a young girl, literally "small one" with the feminine inflection. We picked it up from the Caribbean jazz musicians who began forming a community in New York City in the 1940s. Along with "bebop," originally "rebop," a mis-hearing of
arriba, meaning simply "(kick it) up."