Hurdle vs. Hurtle

Indistinguishable in speech, the words hurtle and hurdle can be a confusing pair.

Hurtle is a verb with two meanings: "to move rapidly or forcefully," as in "The stone was hurtling through the air," and "to hurl or fling," as in "I hurtled the stone into the air." Note that the first use is intransitive: the stone isn't hurtling anything; it itself is simply hurtling. The second use is transitive: something was hurtled—in this case, a stone.

Hurdle is both a noun and a verb. As a noun, its most common meanings have to do with barriers: the ones that runners leap over, and the metaphorical extension of these, the figurative barriers and obstacles we try to similarly overcome. The verb hurdle has two meanings, and they are directly related to these. It can mean "to leap over especially while running," as in "She hurdled the fence," and it can mean "to overcome or surmount," as in "They've had to hurdle significant financial obstacles." The verb hurdle is always transitive; that is, there's always a thing being hurdled, whether it be a physical obstacle or a metaphorical one.