It's interesting question that you have since I have learned english ever..

I learned play the violin when I was young.

>> I learned playing the violin when I was young,

 Long time passed ever since then.

>> A long times has passed since then.

 When I was in school I had to stopped playing the violin.

>> When I was in school I had to stop playing the violin.

 After I graduate high school I started to playing the violin in the university.

>> I started playing the violin after I graduated from the University.

 I am not a very skillful violinist.

>> CORRECT

 But I always try to play it well. Whenever I have a free time I play the violin.

>> CORRECT

 Thanks for asking.

>> CORRECT

 Your question makes me to play the violin more than now.

>> CORRECT

Wow, I am glad to hear that ^^ I play the drums. So, whenever I feel stressed from work. I play the drums. please do the same too ^^