# Research

**[What are the most common mistakes French learners make?](https://blog.duolingo.com/mistakes-in-french-for-learners/)**  
*May 28 [Cindy Blanco, Ph.D.](https://blog.duolingo.com/author/cindy/)*

**[Research report: Our Video Call feature boosts learners’ speaking skills](https://blog.duolingo.com/video-call-research-report/)**  
*Mar 30 [Audrey Kittredge, Ph.D.](https://blog.duolingo.com/author/audrey/)*

**[Research report: Video Call with Falstaff improves beginners’ conversation skills](https://blog.duolingo.com/falstaff-calls-research/)**  
*Mar 10 [Audrey Kittredge, Ph.D.](https://blog.duolingo.com/author/audrey/)*

**[2025 Duolingo Language Report](https://blog.duolingo.com/2025-duolingo-language-report/)**  
*Dec 1 [Cindy Blanco, Ph.D.](https://blog.duolingo.com/author/cindy/)*

**[2024 Duolingo Language Report](https://blog.duolingo.com/2024-duolingo-language-report/)**  
*Dec 1 [Cindy Blanco, Ph.D.](https://blog.duolingo.com/author/cindy/)*

**[Does Duolingo work?](https://blog.duolingo.com/how-well-does-duolingo-work/)**  
*Nov 14 [Duolingo Team](https://blog.duolingo.com/author/duolingo/)*

**[4 learnings from Duolingo efficacy studies](https://blog.duolingo.com/results-duolingo-efficacy-studies/)**  
*Sep 26 [Xiangying Jiang, Ph.D.](https://blog.duolingo.com/author/xiangying/)*

**[Special report: What languages do the French study and why?](https://blog.duolingo.com/what-languages-do-they-study-in-france/)**  
*Mar 11 [Cindy Blanco, Ph.D.](https://blog.duolingo.com/author/cindy/)*

**[2023 Duolingo Language Report](https://blog.duolingo.com/2023-duolingo-language-report/)**  
*Dec 4 [Cindy Blanco, Ph.D.](https://blog.duolingo.com/author/cindy/)*