I would guess it might be a cultural phenomenon, your students might be afraid to speak up unless they are confident they will say it the right way. Maybe it could help if you explain to your students that there is no right & wrong when you are learning language, and making mistakes is an essential part of the process.

i do mistakes I am speking english:-( i don`t can speak it and feel very bad :-(

i always have that feeling.. in talking and writing. Grammar is my no. 1 enemy hahaha

thanks for your advice, kevin. that is my new inspiration, but i don't have any related pic stuff.

There is no magic. Get rid of your promo pic.