What is NACLO?

NACLO is a contest in which high-school students solve linguistic puzzles. In solving these puzzles, students learn about the diversity and consistency of language, while exercising logic skills. No prior knowledge of linguistics or second languages is necessary. Professionals in linguistics, computational linguistics and language technologies use dozens of languages to create engaging problems that represent cutting edge issues in their fields. The competition has attracted top students to study and work in those same fields. It is truly an opportunity for young people to experience a taste of natural-language processing in the 21st century.


  • September 7, 2019Registration for 2020 has started.

    Student registrations are not carried over from one year to the next. If you are a student and had registered prior to September 15, you will need to register again from scratch.

    Site registrations (high school and university sites) are automatically copied from one year to the next.

  • August 12, 2019 The dates for the 2020 contest are January 23 (open round) and March 5, 2020 (invitational round).
  • The NACLO 2019 Student Handbook - to be updated in September.
  • The NACLO 2019 Coordinator Handbook - to be updated in September.
  • The NACLO 2019 Appendix - to be updated in September.

Please Donate

You can help support NACLO either by mailing a check or giving online. For more information on both, please see our donations page. We thank you for your support!


We're looking for new sites and problem contributors. Please contact us at naclo20org@umich.edu.