Duolingo Wiki
Duolingo Wiki

Last version of the language tree (August 2018)

Last version of the language tree (August 2019)

A course's skill tree or language tree is the organization of the course's skills into rows representing the order of course progression. The ones closer to the top are closer to the basics, and as you progress, it will unlock more skills and the skills will get harder as you go on.


The content of a course varies; some courses may contain more vocabulary skills, more grammar skills, or more skills in general than others.  



Main article: Skill

A skill is an item in the tree that consists of one or more lessons. Skills have a levelling system discussed under Crowns to describe how proficient one is in the skill at any given time. Users must level all the skills on each row of the tree to level 1 before moving to the next row.

Skill levels are coloured as follows:

  • 0 = purple
  • 1 = blue
  • 2 = green
  • 3 = red
  • 4 = orange
  • 5 = gold
  • When skills in level 5 start to crack on the edges, it means that you have not been practicing for a while and need to make up for it by doing a lesson. When you complete practices and want to do it again on the same day, the skill will not gain you any XP for the rest of the day.

Bonus skill slots[]

Main article: Bonus skill

Some language trees contain certain slots that can be filled with bonus skills.[1] These can be bought at any time provided that a learner has reached a certain point in the tree. Once the bonus skill has been purchased it remains in the tree permanently.

A Golden Owl as of August 2014

A Golden Owl as of August 2019

As a learner advances through the course their crown level goes up and they unlock new skills. Once they have all of the course's skills at level 1 (finished the tree), they will be awarded a Golden Owl trophy. There are also shortcuts a learner may use to quickly complete the skill tree. These shortcuts include:

  • Placement test - Tests all knowledge of a language tree allowing learners to skip all the skills they already know;
  • Checkpoints - Tests all knowledge of a language tree up to a certain point and once the test is completed it automatically marks all known skills as complete; and
  • Skip level - for people who already know a skill(click the hyperlink for more info)

Tree updates[]

Tree changes.png

Language course contributors continually tweak and update their skill tree. The appearance of the old tree has been changed previously[2] and new lessons or skills may be added or removed to improve the learning experience.[3][4]