Endeavoured vs. Endeavored: Spelling Difference Explained
“Endeavored” is the standard spelling in American English; “endeavoured” is the British English variant. Both are correct within their dialects, so the choice hinges on your intended audience.
People trip up because spell-checkers default to one region and classmates on WhatsApp correct each other in real time. Seeing both in the same feed makes it feel like one must be wrong, when really it’s just geography talking.
Correct Spelling and Rules
In American English, drop the “u”: “endeavored.” British English keeps the “u”: “endeavoured.” The rule follows the same pattern as “color” vs. “colour.”
Common Mistakes
Mixing the two in the same document is the biggest slip. Consistency matters more than which version you pick. If you’re writing for an international brand, lock in one style and stick with it.
Is one spelling more formal?
No—both carry equal weight in their respective regions.
Can I use “endeavoured” in a US college essay?
It’s acceptable, but American professors may mark it as a variant spelling. Stick with “endeavored” to stay safe.