Arbre terminé mais niveau 10 seulement
If you want to get to level 25, you just have to continue to practice because your level is based of the number of XP you get. So just keep your tree golden, and continue to strengthen skills! This comment shows how many XP you need to level up: https://www.duolingo.com/comment/1358479 Good luck, and keep on practicing! You'll get there eventually!
I think this means that you already know some English. If you were learning from the very beginning you would have had to repeat many lessons and so you would have earned more points and your level would be higher. Of course, you can still practice and get your level all the way to 25!