Past Tense of “light”
The past tense of light is lit (also lighted); the past participle is lit (also lighted).
Why “light” behaves this way
"Light" (the verb, meaning to ignite or illuminate) comes from Old English "lihtan," related to the adjective "leoht" (light, as in not heavy, and also light, as in brightness — themselves two historically related senses in Old English, both tracing back to a root about weightlessness and brightness that speakers eventually treated as separate words). The verb's irregular past tense "lit" developed relatively late by analogy with other short, vowel-shifting irregular verbs, alongside a fully regular alternative, "lighted," that has never entirely disappeared and remains equally correct in most contexts.
"Light" (illumination) and "light" (not heavy) being historically related rather than coincidental look-alikes is unusual — most English homographs are entirely unconnected words that happen to converge in spelling, but here the connection runs through an old, broader root sense that no longer feels intuitive to modern speakers, since brightness and lack of weight don't feel conceptually linked today the way they apparently once did to earlier English speakers.
The common confusion
Choosing between "lit" and "lighted" isn't so much a source of confusion as a functional split, since both are accepted: "lit" is generally preferred as a plain verb form ("she lit the candle"), while "lighted" survives more often as a pre-noun adjective in slightly more formal or literary contexts ("a lighted window"), a soft stylistic tendency rather than a hard rule.
How it's actually used
"Light" extends figuratively into emotional brightening — "her face lit up," "the news lit up the room" — a metaphor so natural in English that it barely registers as figurative anymore, alongside its more literal senses of physically igniting something or illuminating a space. "Lit" has also recently developed a completely separate, purely slang adjectival meaning ("that party was lit," meaning excellent or exciting), a 21st-century usage entirely unrelated grammatically to the verb's conjugation, functioning as a standalone adjective rather than any tense of "light." Theater lighting design uses "lit" as precise technical shorthand ("the stage is lit from the wings"), a professional usage distinct from casual descriptions of ordinary illumination.
Across the tense system
"Lit up" as a phrasal verb spans both literal (turning on lights, igniting something) and figurative (an expression brightening with emotion) senses across every tense, while the newer slang adjective "lit" (excellent, exciting) never conjugates at all and shouldn't be mistaken for a verb form, since it's grammatically frozen as a standalone descriptor. Photography preserves the technical noun "exposure," built on how much light reaches film or a sensor, and separately uses "light meter" as a fixed compound noun, both specialized vocabularies that grew up alongside the verb without ever borrowing its lit/lit conjugation directly. "Light up" also describes a cigarette being ignited, a once-neutral everyday use now often carrying a slightly dated or specifically smoking-related connotation compared to its broader senses of igniting or brightening.
Common real mistakes
There's little grammatical error potential here since both "lit" and "lighted" are accepted, but writers occasionally reach for "lighted" in every context out of a mistaken belief that it's the more "correct" or formal choice, when in fact "lit" is the more common and often more natural-sounding option in ordinary verb use. A separate, purely stylistic confusion is younger writers using slang "lit" (meaning excellent) in formal writing where it reads as out of register, unrelated to any actual grammatical mistake. Some writers also mistakenly treat "enlighten" as a simple synonym for "light," when the prefixed verb has drifted entirely into a figurative sense of imparting understanding, with no remaining connection to physical illumination at all.
Examples
- She lit the candles before the guests arrived.
- He has lit a fire every evening this winter.
- They lit up the whole street with decorations.
- We had lighted the path with lanterns for the ceremony.
- The room lights up beautifully at sunset.
- Her face lit up when she saw the gift.
- The building is lit entirely by solar panels.
- They're lighting the fireworks now.
Memory trick
Default to "lit" for almost everything — igniting, brightening, someone's face lighting up with joy — and reserve "lighted" mainly for describing a noun directly before it ("a lighted sign"), a soft stylistic preference rather than a strict rule you need to enforce everywhere.