vibrato

I can do vibrato but i cant to it on comand. its like i know how sing vibrato but when i do exercises i cant vibrato, but when i sing something vibrato just comes naturally. i dont know how to fix that or even if i should that.

Good question! Vibrato is a naturally occuring event, so it's great that you're not forcing it and you're hearing it come in naturally! For some styles of music, we may want more or less vibrato - so I recommend you check out this tutorial  for instruction related to that. 

But really, I wouldn't be concerned! Eventually, see if you can sustain your vibrato (when it comes naturally), then go from vibrato to straight tone, then from straight tone to vibrato. That way, you'll start to learn what it feels like to "release" and withhold your vibrato so you can then add vibrato in specific places. 

thanks alot camille!

No problem, Aviv!