Past Tense of “spoil”
The past tense of spoil is spoiled; the past participle is spoiled.
Why “spoil” behaves this way
"Spoil" comes from Old French "espoillier" (to strip, plunder, or despoil), itself from Latin "spoliare," the same root that gives English "spoils of war" and "despoil." The original sense was specifically about stripping an enemy of armor or plunder after a battle, and only later, through the notion of something being ruined or robbed of its value, did the meaning broaden to today's general sense of something going bad or being ruined.
"Spoiled"/"spoilt" is another member of the British t-preterite family alongside "spelled/spelt" and "spilled/spilt," with the same regional pattern: American English uses "spoiled" almost exclusively, while British English uses both, with "spoilt" often specifically favored in the adjectival sense describing an overindulged child ("a spoilt brat") even by speakers who might use "spoiled" for the literal sense of ruined food. Historically, "spoil" entered English already as a Latinate loanword conjugating like a native weak verb from the start, so unlike "slit" or "speak," it never went through a strong, ablaut-based stage in English at all — the t-preterite variant is simply a later regional spelling divergence rather than evidence of any older strong conjugation.
The common confusion
The adjective "spoiled"/"spoilt," describing a child who has been overindulged, has become almost a fixed compound in its own right ("spoiled rotten"), and some writers hesitate over whether this adjectival use should follow the same regional spelling rules as the literal sense (ruined food, a ruined plan) — it does, but the two senses feel different enough in meaning that the connection isn't always obvious.
How it's actually used
"Spoil" covers a wide range of senses beyond food going bad: spoiling a surprise (revealing it prematurely, the source of the modern noun "spoiler"), spoiling a child (overindulging), spoiling a ballot (marking it invalidly), and spoiling for a fight (eagerly seeking conflict) — a remarkably productive verb whose core sense of "ruining potential or value" stretches across food, plans, character, and elections alike. The idiom "spoiling for a fight" is particularly interesting because it's one of the few uses where "spoil" carries a positive-feeling eagerness rather than its usual negative connotation of ruin or decay, an unusual semantic outlier within the verb's broader family of meanings.
Across the tense system
The passive voice is standard for the literal food sense ("the milk was spoiled by the heat") and for the ballot sense ("thousands of votes were spoiled due to unclear instructions"), while the child-related adjectival sense functions more like a stative description than a true passive action, closer to "the child is spoiled" describing an ongoing trait than "the child was spoiled" describing a specific completed event. The perfect tense also carries a distinct nuance in the surprise-revealing sense: "the ending has been spoiled for me" describes a state of already knowing, while "someone spoiled the ending" more directly names a completed, blameworthy act, a distinction readers of online spoiler warnings navigate constantly without necessarily noticing the grammar behind it.
Common real mistakes
The main practical error, again, is drifting between "spoiled" and "spoilt" inside one document rather than any actual incorrectness. A second, distinct error is using "spoil" to mean simply "damage" or "break" in contexts where a more precise verb is expected, since "spoil" specifically implies something going bad or losing its intended value or purpose rather than mere physical damage — a car can be "damaged" in an accident, but calling it "spoiled" would sound oddly imprecise to most readers. A third error, common in film and television writing, is treating "spoiler" as if it must relate grammatically to a specific verb tense, when in fact it's simply a noun derived from the verb's warning-related sense (something that spoils a surprise) and doesn't itself conjugate.
Examples
- The milk had spoiled by the time they got home.
- He spoiled the ending before anyone else had seen the film.
- They spoilt their daughter with gifts every holiday.
- The picnic was spoiled by the sudden rainstorm.
- Thousands of ballots were spoiled due to a printing error.
- The trip had already been spoiled by the delayed flight.
Memory trick
Same geography rule as "spelt" and "spilt": "spoiled" is the universal safe choice, "spoilt" is the marked British variant — and remember it applies just as much to an overindulged child ("spoilt rotten") as it does to milk left out too long on the counter.