You can do translations for the subject, repeat your lessons and do lessons on other subjects. :)

Are you talking about testing out of a skill? Testing out of a skill is a shortcut, so if you fail that, it means you don't know the material well enough to take the shortcut. You have to go through the lessons the long way. You don't get points for repeating a lesson because you've already done it and earned the points for it. Does that make sense?

Well, by doing those things, you will gain coins on the subject and if you have enough coins, you reach the Master level manually, instead of testing out of it. :)

If you continue to use translations and repeat the refresher, you will eventually master the skill. The testing is just a shortcut.

I thank you for your input, but it doesn't answer my question: "How can you master the skill after having failed those three attempts?"

I have repeated (today) a lesson from the skill where I have failed the three attempts (yesterday) and I have earned "+0" points for it. Can you explain this?

Thank you, csi and radh!

You just continue doing the lesson until you have gathered a set amount of points or gold coins. Just like it takes a specific amount of coins to "learn" a lesson, it takes a specific amount to "master" it if you don't take the shortcut. So, just repeat the lesson over and over until you have actually "mastered" it as it were.