Q: I've seen it written both ways: "leaped" and "leapt." Which is correct? —Tony V.
A: He leaped off the building. She leapt off the building. This may surprise you, but both "leapt" and "leaped" are acceptable past-tense and past-participial forms of the verb "leap." It's fine to use either one.
According to Garner's Modern American Usage, traditionalists prefer "leapt," so if you want to keep the grammar curmudgeons happy, stick with that. But if you're more of a nonconformist (and I'm TOTALLY a nonconformist), choose "leaped" so you can feel like a rule-breaker (even if you aren't actually breaking any usage rules).
The only common error sneaking its way into the works is "lept," which is just a misspelling of "leapt." Avoid that, and you'll be fine.