Two rounds. Five problem types. Six hours of language reasoning.
The International Linguistics Olympiad runs two consecutive rounds each summer — a six-hour individual contest and a three-to-four-hour team contest — for secondary-school students from forty-two participating countries. No prior linguistics is assumed; every problem is solvable from a short corpus and careful reasoning.
Eligibility — secondary-school students, age-gated by national selection.
IOL is open to secondary-school students typically aged 13 to 18. Each participating country runs its own national olympiad as a selection round; the top finishers in that national round form the country’s delegation to IOL. Most national olympiads accept students from grade 7 up.
To compete at IOL itself, a student must first qualify through their country’s national selection — we cannot enrol students directly. We can, however, help you find your national olympiad and recommend the sample problems that match its difficulty.
If your country does not yet have a national olympiad, the IOL Board accepts a small number of guest delegations; eligibility is reviewed case-by-case and the deadline is typically the end of February each year. See ioling.org for current guest-delegation policy.
Five problems, six hours, one solver.
The individual round is the longer and more famous of the two. Each contestant receives a packet of five problems spanning a range of linguistic phenomena, and has six hours to solve as many as they can. Working alone, with paper and pen only.
How a problem looks
A typical problem opens with a short corpus: ten to twenty sentences, phrases, or numerals in a language the contestant has never seen before, with English glosses for some but not all of them. The task is to derive the underlying linguistic pattern — phonology, morphology, syntax, semantics, or numeral system — and then apply it to predict or translate previously unseen forms.
The languages chosen are often endangered, lesser-studied, or otherwise unlikely to have appeared in any school curriculum. Knowing the language is no advantage: the problem is solvable from the data alone, and prior speakers of the target language are not allowed to compete on problems featuring their first language.
Each contest covers five categories, one per problem.
Phonology
Sound systems, vowel harmony, tone, stress patterns — reconstruct the rules from glossed data.
Morphology
Word formation, agglutination, inflection paradigms — deduce affix order and stem alternations.
Syntax
Word order, sentence structure, agreement — figure out how complex meanings are built from words.
Semantics & pragmatics
Meaning, kinship terms, deictic systems, conventional implicature — understand context-bound usage.
Numeral systems
Decimal, vigesimal, mixed-base counting — deduce the arithmetic structure from glossed numbers.
One extended problem, three to four hours, four solvers.
The team round is held on a separate day from the individual round. Each delegation’s four contestants work together on a single, much larger problem — typically running fifteen to twenty pages of data and analysis — with three to four hours to complete it.
The team problem is usually open-ended: instead of asking solvers to predict specific forms, it asks them to construct a grammar, a writing system, or an analysis of a complex linguistic phenomenon from a corpus of evidence. Partial credit and elegance of reasoning matter as much as final answers.
Team scores combine into both an aggregate team ranking and individual team medals. The team round is widely regarded as the most enjoyable part of IOL by past contestants — the collaboration changes the texture of the puzzle entirely.
Four tiers, set by cut-offs on individual-round scores.
Medals are awarded based on each contestant’s individual-round score, with cut-offs set after the contest. The team round produces its own separate ranking. Approximate proportions are based on past contests; final cut-offs vary year-to-year.
Gold
Highest individual scores. Typical cut-off lands around 75 – 85 of 100 possible points, though this varies sharply by year and problem set.
Silver
Strong individual performance. Most silver medalists solved three to four problems completely with partial credit on the others.
Bronze
Solid individual round. Typically two complete solutions plus meaningful progress on additional problems.
Honourable mention
Awarded for solving any single problem completely and elegantly, even if total score did not reach the bronze cut-off. Recognises specialty over breadth.
Best Solution awards are also given for the most elegant solution to specific problems, separate from the medal tiers. Final cut-offs and award lists for any given year are published on ioling.org within a week of the closing ceremony.
What you can and can’t bring into the contest hall.
These rules apply during both rounds. The IOL Board publishes the full official regulations on ioling.org; below is a plain-language summary for student preparation.
ALLOWEDWhat you can bring
- +Pens and pencils — any number, any colour. Most solvers bring 3 – 4 sharpened pencils plus a couple of pens for final answers.
- +Erasers and pencil sharpeners — non-electronic.
- +Rulers and protractors — useful for laying out grammar tables and morpheme charts.
- +Water bottles — non-tinted, label removed (the contest hall provides water during long sessions).
- +Snacks — small wrapped items only. The individual round runs through lunch.
NOT ALLOWEDWhat stays outside
- ×Any electronic device — phones, smartwatches, calculators, dictionaries, headphones. All collected at the door.
- ×Paper dictionaries or reference books — the contest is a closed-book test of reasoning.
- ×Notes from prior preparation — you cannot bring grammar cheat-sheets, formula cards, or training notes.
- ×Communication with anyone outside the contest hall during the rounds. Bathroom breaks are supervised.
- ×Problems featuring your first language — if a problem uses a language you speak natively, you are excused from that problem (and given a replacement).
The 23rd IOL convenes in Bucharest, 26 July to 2 August 2026.
Hosted by the University of Bucharest’s Faculty of Letters, the eight-day programme combines two contest days with cultural excursions, opening and closing ceremonies, and a jury session for delegation leaders. Below is the typical IOL week structure; exact dates for 2026 are published on ioling.org.
Arrival & opening
Delegations arrive in Bucharest. Registration. Opening ceremony at the University of Bucharest. Welcome dinner for contestants and team leaders.
Excursion & jury
Contestants on a cultural excursion (typically Bran Castle or Sinaia). Team leaders convene the international jury to finalise individual-round problems.
Individual round
The six-hour individual round runs in the main contest hall. Five problems, single sitting, paper-and-pen. Contestants typically leave the hall in the late afternoon.
Excursion & marking
Contestants on a second excursion. Markers begin grading individual-round papers. Team leaders translate team-round problem into delegation languages.
Team round
The three-to-four-hour team round. Each delegation’s four contestants collaborate on a single extended problem.
Coordination
Cross-delegation coordination: markers reconcile scores and discuss borderline cases with each team’s leaders. Contestants on an additional excursion or rest day.
Excursion & preparation
Final day of excursions. Award ceremony rehearsal in the evening. Cut-offs for gold, silver, bronze, and honourable mention are confirmed by the jury.
Closing ceremony
Medal presentations, best-solution awards, and closing remarks. Handover to the host delegation of IOL 2027. Departures begin in the evening.