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EN 601.468/668 Machine Translation
Fall 2023
Tuesdays and Thursdays 1:30-2:45
Room: Maryland 110
Computer Science Department
Johns Hopkins University

Google translate instantly translates between any pair of over eighty human languages like French and English. How does it do that? Why does it make the errors that it does? And how can you build something better? Modern translation systems like Google Translate and Bing Translator learn to translate by reading millions of words of already translated text. This course will show you how they work. We cover fundamental building blocks from linguistics, machine learning (especially deep learning), algorithms, and data structures, showing how they apply to a difficult real-word artificial intelligence problem.

Philipp Koehn (
Haoran Xu (
Office hours
Professor by Appointment
TA Tuesday 3-4pm, Hackerman 2nd floor, kitchen area
This class will be delivered in person this year. Lectures were pre-recorded last year and these are still accessible through links on this web site and on Youtube.
Discussion Forum
Piazza access code: 8dk9w3pxe8w ! Gradescope access code: 7DGJ6D
The class follows closely two textbooks.
To understand how machine translation works, you will build a translation system. We will mainly grade hands-on work.
  • Five homework assignments (12% each)
  • Final project (30%)
  • In-class presentation: Language in ten minutes (10%)
Homework Schedule
There will be five homework assignments, tentative schedule:

Late penalty for homework assignments: 10% per day, after 5 free “late days”.