Prompt to choose between timed and untimed practice
The Strengthen skills button provides an exercise practice/review of material learned in lessons, with a focus on the material that Duolingo believes the user most needs practice in at that moment[1]. Such practices are untimed by default, however a timed practice option is also available for purchase in the Lingot Store.
Successfully completing a practice session results in strengthening the words practiced[2] and, if enough words from the same skill are strengthened, also strengthening that skill. However, it may take one or more tries to fully strengthen a skill[citation needed].
Purpose
"Strenghten skills" helps users to:
- Memorize;
- Test their knowledge;
- Review learnt material; and
- Maintain and improve their skills.