Past Tense of “outdo”
The past tense of outdo is outdid; the past participle is outdone.
Why “outdo” behaves this way
"Outdo" is "out-" plus "do," and it inherits do's ancient three-part irregular pattern (do/did/done) intact, a pattern going back to Old English "don/dyde/gedon." "Do" is a workhorse verb English leans on constantly, both as a main verb and as the auxiliary behind questions and negatives, and that sheer frequency of use is exactly what shields its irregular forms from being smoothed over by analogy the way rarer verbs sometimes are; "outdo" simply rides along with whatever "do" does, prefix and all. The word appears in Shakespeare and in earlier Tudor-era prose, always carrying the same competitive sense it has today, which is unusually stable for a verb this old — many 16th-century compounds have drifted wildly in meaning, but "outdo" reads almost exactly the same to a modern eye as it did four hundred years ago.
The prefix "out-" meaning "to surpass" or "exceed" has been productive in English since Old English times (compare "outlive," "outgrow," "outrun"), and "outdo" specifically has been in continuous use since at least the 16th century in the competitive sense of "do better than." Because "do" retains its full historical irregularity even in modern speech — unlike some Old English strong verbs that have regularized over time — "outdo" never had an opportunity to simplify either.
The common confusion
Writers occasionally reach for "outdid" as the past participle ("has outdid himself") instead of the correct "outdone," collapsing the three-form do/did/done pattern down to two forms the way some speakers do with "do" itself in casual speech. The distinction matters more here than with plain "do" because "outdone" shows up constantly in the fixed idiom "not to be outdone," which never uses "outdid."
How it's actually used
"Outdo" is almost always reflexive or comparative in modern use — "outdo yourself," "outdo the competition," "not to be outdone" — and rarely appears as a plain transitive verb without that competitive framing. The idiom "outdo oneself" specifically uses the past participle in its most common form: "you've outdone yourself." It also appears frequently in marketing and self-improvement writing ("outdo your best time," "outdo last year's results"), where the reflexive framing turns a simple comparison into a motivational device rather than a statement about beating a specific rival. Sibling rivalry stories lean on this verb constantly, precisely because it captures ongoing, good-natured competition rather than a single decisive victory.
Across the tense system
Like "do," "outdo" needs its participle form for every perfect and passive construction: "has outdone," "had outdone," "will have outdone." The simple past "outdid" is reserved strictly for the straightforward past-tense narrative ("she outdid her rival"), never for perfect-tense constructions. In spoken English, some dialects informally flatten "outdid" and "outdone" toward a single form the way "do" itself sometimes gets flattened in nonstandard speech ("I done it"), but formal writing should always keep the two forms distinct.
Common real mistakes
The most common slip is "has outdid" instead of "has outdone," essentially importing the everyday nonstandard "I done that" pattern in reverse. A second error is dropping the "out-" prefix's implied comparison and using "outdid" as if it just meant "did," losing the competitive sense the prefix supplies. Writers drafting quickly under time pressure — resumes, social captions, quick emails — are the most frequent source of the "has outdid" slip, since the correct "outdone" requires an extra mental step that "outdid" skips. A further point: some writers mistakenly hyphenate the compound as "out-do," a nonstandard spelling; standard English always writes it as one unbroken word, both as a verb and in its inflected forms.
Examples
- She outdid herself with this year's holiday dinner.
- He has outdone every previous record in the company.
- Not to be outdone, the younger team doubled their effort.
- They outdid their rivals in every category at the fair.
- The bakery outdid itself with this year's wedding cake designs.
- No sequel has outdone the original film, critics agreed.
- Rival bakeries kept trying to outdo one another every holiday season.
- Each new tour seems designed to outdo the pyrotechnics of the last.
Memory trick
Whatever "do" does, "outdo" does too, just one better: do/did/done becomes outdo/outdid/outdone in lockstep, prefix riding along unchanged.