Past Tense of “rethink”
The past tense of rethink is rethought; the past participle is rethought.
Why “rethink” behaves this way
"Rethink" combines "re-" with "think," whose irregular past form "thought" comes from an Old English strong verb pattern with a consonant shift ("thencan" to "thohte"), one of the more phonetically distant irregular transformations in the language, since "think" and "thought" share almost no surface sound similarity beyond the initial "th-." "Rethink" inherits this pattern directly, and the compound has meant "to reconsider or think through again" since at least the 19th century, a comparatively recent formation next to older prefixed verbs like "rebuild" or "repay." Urban planning literature specifically credits certain influential mid-20th-century thinkers with prompting cities to "rethink" car-centric design, a use so associated with that particular movement that the phrase "rethinking the city" became something of a genre title in planning literature.
"Rethink" saw a notable rise in business, policy, and design writing during the 20th century, where "rethinking" a strategy, a process, or an approach became a favored way to signal deliberate, fundamental reconsideration rather than minor adjustment — the word carries a connotation of starting closer to first principles than simply "reconsidering" or "revising" something does. Design-thinking methodology, popular in corporate innovation workshops since the early 2000s, treats "rethinking" a problem from scratch as a formal, structured first step, giving the verb near-technical status in that specific professional subculture.
The common confusion
One form, "rethought," quietly does the job of both past tense and participle here, but the spelling itself trips people up: because "think" and "thought" sound so little alike compared with transparent pairs like "walk/walked," some writers half-expect a form closer to "rethinked" and second-guess themselves needlessly.
How it's actually used
"Rethink" is a favorite in business strategy, design, and policy writing ("rethinking the customer experience," "rethinking urban transportation"), almost always implying a deliberate, thorough reconsideration rather than a quick or casual change of mind. Environmental and sustainability writing frequently calls for "rethinking" consumption habits or supply chains, using the verb to signal a demand for structural change rather than incremental adjustment. Product-design retrospectives frequently conclude that a team needs to rethink a feature entirely rather than iterate on it, a recommendation that carries real budgetary and timeline consequences. A single bad quarter is sometimes enough to make a whole leadership team rethink its five-year plan. A founder willing to rethink a core assumption early often saves years of wasted effort compared with one who defends the original plan out of stubbornness alone. A single customer complaint rarely triggers a full rethink, but a pattern of them almost always does. A close election loss is usually enough to make even a confident incumbent rethink their entire platform.
Across the tense system
"Rethought" covers both grammatical roles without changing at all, so "the company rethought its strategy" and "the company has rethought its strategy" only diverge based on whether an auxiliary comes before it. Opinion journalism frequently opens with an imperative framing ("it's time to rethink...") rather than any past-tense description, since persuasive essays typically argue for future reconsideration rather than narrate a completed one.
Common real mistakes
The main error is treating "rethink" as regular and writing "rethinked," a mistake that occasionally appears in casual or nonnative writing but is quickly noticeable to fluent readers given how well-established "think/thought" is. A further point: "rethink" implies genuine reconsideration of fundamentals, so it reads oddly applied to a trivial, minor adjustment.
Examples
- The city rethought its entire public-transit strategy after the survey results.
- She has rethought her career path more than once in the past decade.
- They rethought the product's design after early user complaints.
- The board rethought its stance following the shareholder meeting.
- The panel urged policymakers to rethink how cities handle stormwater runoff.
- After the backlash, the company rethought its entire pricing model.
- The retrospective concluded the team needed to rethink onboarding from the ground up.
- A disappointing quarter pushed the whole leadership team to rethink its pricing strategy.
Memory trick
Follow "think": think, thought, thought becomes rethink, rethought, rethought — the consonant shift (k to ght) carries over exactly, even though the sounds barely resemble each other.