They haven't earned all their money, I think they bought coins with real money, even you can unlock all the lessons but with 25$. The most important is improve your English with this app to your benefit.

Do you do exercise in the morning, at 5 o'clock? is the present like routing of every day Did you do exercise at 5 o'clock, in the morning? something that happened in the past and use DO exercise, because is an activity do yoga , do kunfu,etc..