Past Tense of “bite”
The past tense of bite is bit; the past participle is bitten (also bit, especially in fixed phrases).
Why “bite” behaves this way
"Bite" descends from Old English "bitan," part of the same historical strong-verb family as "write" and "ride" (bitan/bat/biten); the long-i-to-short-i-to-long-i-plus-en vowel pattern carries through all three the identical long-i-to-short-i-to-long-i-plus-en vowel pattern across their present, past, and participle forms today.
The fixed phrase "bit the bullet" (endured something difficult or painful) preserves the older, unchanged past-tense form even in contexts where "bitten" would otherwise be expected grammatically, and the idiom's popular origin story — soldiers biting a bullet during battlefield surgery without anesthesia — is likely at least partly folk etymology rather than confirmed documented history, though the phrase's meaning of gritting one's teeth through hardship has remained stable regardless.
The common confusion
The genuine confusion is knowing when "bit" alone (without the auxiliary) is acceptable versus when "bitten" is required: standard grammar calls for "bitten" after "have/has/had" ("the dog has bitten someone before"), but a handful of fixed idiomatic phrases, like "once bitten, twice shy," keep the older participle form specifically because it's frozen into a set expression.
How it's actually used
"Bite" extends widely into figurative senses of harsh effect — cold "bites," criticism "bites," a market downturn "bites" — all describing something painful or sharp without any literal use of teeth. "Bite off more than you can chew" (take on more than you can handle) and "the biting cold" (severe, sharp cold) both extend the literal sense of teeth into metaphors of overwhelming difficulty or intensity. Snake and insect bites carry a specific medical vocabulary built on this verb ("a venomous bite," "bite mark"), a literal clinical use distinct from every figurative sense discussed above. "Bite the dust" (to fail, or die, often used humorously) and "put the bite on someone" (an older slang phrase meaning to pressure someone for money) are two further idioms extending the verb's core sense of a sharp, sudden action into entirely different domains.
Across the tense system
"Bitten" functions independently as an adjective describing someone affected by an enthusiasm or obsession ("bitten by the travel bug"), a lighthearted figurative use distinct from its literal sense describing an actual physical bite from an animal or insect. Dental and forensic science use "bite" as a specialized noun ("a bite mark," "bite alignment") in contexts ranging from orthodontics to criminal investigation, a precise technical use built directly on the verb's literal sense of teeth pressing into something.
Common real mistakes
The most frequent real error is dropping the -en ending after have/has/had ("has bit" instead of the standard "has bitten"), a slip common in casual speech but flagged in careful formal writing outside the small set of fixed idioms that legitimately keep the shorter form. Learners occasionally also confuse figurative "bite" (harsh effect) with literal "bite" (using teeth) in translation from languages that use entirely separate verbs for the two senses. Another point that trips learners up is telling "bite" apart from "sting," since insects can do either depending on the species, and English requires the correct verb for each — a bee "stings" while a mosquito "bites," a distinction with real consequences for accurate, natural-sounding descriptions. A final idiomatic note: "what's biting you" (an informal question asking what's bothering someone) uses the verb figuratively for irritation or worry, distinct from any of the other figurative senses of harshness or intensity discussed above.
Examples
- The dog bit the mail carrier last week.
- She has been bitten by mosquitoes all summer.
- He bit his tongue rather than argue further.
- We had bitten off more than we could chew with this project.
- The cold bites hard once the sun goes down.
- Once bitten, twice shy, as the saying goes.
- She's biting her nails out of nerves.
- He bit the bullet and finally called the dentist.
Memory trick
Group "bite/bit/bitten" with "write/wrote/written" and "ride/rode/ridden" as sharing the same ancient long-vowel-to-short-vowel-to-en pattern, and remember standard grammar wants "bitten" after have/has/had — the bare "bit" versions survive only in specific frozen idioms like "bit the bullet."