NACLO at Yale

What is NACLO?

North American Computational Linguistics Open

An international contest for high school and middle school students in which they solve linguistics problems drawn from a variety of languages. Only logic and reasoning skills are necessary; no prior knowledge of languages or linguistics is required. 

The first competition was held in 2007 in the US, and grown since. Since 2013, Yale University has served as a local site for NACLO, which means that students can attend training sessions and participate in the competition on Yale’s campus. 

National NACLO organization
Stained glass window depicts a printer removing a page from a printing press while another inks text-blocks

Open Round 

When: Thursday, January 23, 2025, from 10:00am until 1:00pm

Where: Dixwell-Yale University Community Learning Center: 101 Ashmun St, New Haven, CT 06511 [note that this is a new location!]

Students should plan to arrive to 101 Ashmun St by 9:30 to have time to settle in and be ready to start at 10:00 sharp. 

The competition is very challenging and is designed for high-school students. Middle-school students are welcome to participate as well, but we recommend this only for those middle-school students who are especially well-equipped to deal with this kind of academic challenge.

If you have any questions about the training sessions, or about the NACLO contest at Yale, send an email to Profs. Tom McCoy or Raffaella Zanuttini at yalenaclo@gmail.com.

Register for the open round

Training Sessions 

The sessions will take place between 2:00pm and 4:00pm on the following Sundays: 

  • November 10, 2024
  • December 8, 2024
  • January 19, 2025

Register for training sessions

Be sure to register before the training sessions!

This helps us track where students are training. You can also register on site the day of training.

Register for training sessions

How does it work?

  • Training: The Yale Department of Linguistics hosts training sessions to provide information about NACLO and to allow students to try out practice problems. Sessions are typically held on Yale campus in the fall and early spring.
  • Open Round: Anyone can enter the free open competition! Yale campus is one of the local hosts of the open round. 
  • (Second) invitational Round: Students who perform well in the Open round will be invited to take part in the second (Invitational) round. 
  • International Linguistics Open Round: The top students in the invitational round from across North America will have a chance to participate in the International Linguistics Open competition in the summer. 
Students at the NACLO Open Competition, holding up an American flag and smiling

Contest info

Visit the NACLO website to register, access practice questions, and more. 

NACLO practice problems NACLO open round registration

Sample question: Cat and Mouse Story

“Okay, so my cat pombled gwee the trowby, and she pombled gwee the foba. She pombled ippip the foba and pombled gorch the foba, and eventually she pombled ippip the trowby.”

Your friend has apparently joined some strange new subculture and is trying out the slang. Either that or he hit his head. Whatever the cause, it looks like your friend has replaced the words down, into, up, run, mouse, and street with the words gwee, ippip, trowby, foba, pomble, and gorch. You can’t yet tell which is which, so you have this conversation:

You: So, it started off with the cat pombling the trowby gwee.
Him: That’s nonsense; that’s not even a good sentence.
You: Could I say “The cat pombled the foba gwee?”
Him: That’s just as bad.
You: It was gwee the foba that the cat pombled, right?
Him: Correct.
You: Then the cat pombled gorch the foba and ippip the foba.
Him: Yes.
You: And the cat pombled gorch the foba and ippip the trowby?
Him: You’re talking nonsense again.
You: But it was ippip the trowby that the cat pombled?
Him: You don’t know how to use words, do you?
You: The cat pombled the trowby ippip.
Him: That sounds a lot better.

What do the following words mean? Context clues are useful to give you hints, but to prove which words mean which, you should also use your friend’s judgments about your attempted sentences.

foba:
ippip:
gwee:
pomble:
gorch:
trowby:

History of NACLO at Yale

Hosting NACLO at Yale was an initiative undertaken by Tom McCoy (YC ‘17), Aidan Kaplan (YC ‘17), and Raffaella Zanuttini. Tom McCoy was an undergraduate student at the time. He has returned to the department as a faculty member in 2024. 

Headshot of Tom McCoy