English UsageComparison guide
Speeded vs. Sped
Both “sped” and “speeded” are documented past-tense and past-participle forms of “speed.” The choice can depend on construction and style rather than a universal correctness rule.
Both “sped” and “speeded” are valid past forms of “speed”; choose the form that fits your construction and style.
Key details
Confusion Familyalternative past forms
Rule Familyverb-forms
TermsSpeeded, Sped
Further guidance
Core difference
Both “sped” and “speeded” are documented past forms of “speed.” Cambridge explicitly lists both with “speed up.”
Usage Boundary
Because both forms are standard in documented use, avoid presenting one as universally wrong. Follow the construction, regional preference, and house style that fit the sentence.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Speed (something) up — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · Dictionary evidence that both “sped” and “speeded” are documented past forms of speed, including speed up.