What is NACLO?

NACLO is a contest in which high-school students solve linguistic problems. In solving these problems, 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.


  • June 4, 2022The solutions have also been released.
  • April 28, 2022The problem booklets from 2022 have been released.
  • April 20, 2022Grading for the 2022 Invitational Round has concluded. The results and team assignments can be accessed here. The Open Round and Invitational Round problems and solutions will be posted shortly. Thank you for participating!
  • March 7, 2022Grading for the 2022 Open Round has concluded and your score is available in your student account. The list of students who have qualified for the Invitational Round has been released. You can access it here. Please contact naclo22org@googlegroups.com if your score is missing.
  • March 7, 2022The results from the Open Round will be posted to the student accounts later today, March 7.
  • March 5, 2022The jury is finalizing the Open Round grading and results will be announced in the next few days. In the meantime, here is the list of submitted booklets. If you don't see your ID/registration number in this list, please contact naclo22org@googlegroups.com as soon as possible.
  • February 9, 2022The 2022 Open Contest is over. Registration for the 2023 Open Contest will start in late September, 2022.
  • September 26, 2021Registration for the 2022 Open Contest has started.
  • September 19, 2021The handbook for 2022 is now available.
  • August 16, 2021NACLO 2022 will be on January 27 and March 17, 2022

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 naclo22org@googlegroups.com.