OmegaLearnHow to Prepare for NACLO (North American Computational Linguistics Open)
Middle/HighWhat is NACLO?
NACLO (the North American Computational Linguistics Open competition) is a contest in which students solve self-contained puzzles about human language and how computers process it. No prior knowledge of linguistics, foreign languages, or programming is required โ every problem gives you all the data you need, and success comes from logic, pattern recognition, and creativity. It runs in two stages: an Open Round of eight problems in three hours, followed by an invitation-only Invitational Round. Top scorers are selected for the US and Canadian teams at the International Linguistics Olympiad (IOL).
Format
The Open Round is a three-hour written test with eight problems labeled AโH. You may take it individually or as part of a team, writing all solutions by hand. Partial credit is awarded.
Who can enter
Open to students in grades 7โ12 in the United States and grades 8โ12 in Canada. It is free to enter, and no linguistics or language background is expected.
When & how
The Open Round is held each winter (late January), at university host sites or online. Students who score well are invited to the Invitational Round in March.
How to advance
About one hundred top Open Round scorers advance to the Invitational Round. The highest Invitational scorers form the US and Canada teams for the International Linguistics Olympiad.
Official Information
NACLO official website
The home of the North American Computational Linguistics Open competition, with registration, dates, and everything a new contestant needs.
View โHow to register
Details on finding a host site, registering, and taking the Open Round either at a university site or online.
View โ2026 Student Handbook
The official rules, format, eligibility, and conduct guidelines for contestants in the current cycle.
View โCountry & grade eligibility
Confirms who may compete: students in grades 7โ12 in the US and grades 8โ12 in Canada, subject to IOL rules.
View โNACLO overview (Wikipedia)
A neutral overview of NACLO's history, structure, and its role in selecting teams for the International Linguistics Olympiad.
View โPractice Tests
NACLO publishes every past problem set with full solutions, and working through them is by far the best preparation. Take a full Open Round under real conditions โ three hours, no references โ then grade yourself against the official solutions.
NACLO past problems archive
Full Open and Invitational Round booklets with solutions going back to 2007 โ the best practice source available, all free.
View โNACLO resources page
Year-by-year links to problem sets, solutions, and sample problems, including UK Linguistics Olympiad samples.
View โIOL problems & solutions
International Linguistics Olympiad problems, the next level of difficulty after NACLO's Invitational Round.
View โPaid Courses & Classes
NACLO is designed to be prepared for almost entirely with free past problems, so dedicated paid courses are few. A couple of programs do offer structured coaching for students who want it.
SpringLight Education: NACLO Training
A structured NACLO prep course teaching the main puzzle types and problem-solving strategies through past problems.
View โPEN Academy: Linguistics Competitions
A weekly NACLO/IOL prep class taught by a coach with 15+ years of experience, focused on associative, scientific, and algorithmic thinking.
View โ