I had to learn Chinese when I lived in China.  I also was subject to
criticism, even though English is my native language.  I think it is not
always a bad thing to be criticised.  I know that it helped me improve my
Chinese .  All criticism is not malicious.  Some criticism is constructive.
 I think, however, it is quite important for those who live and work in
America to practice effective language skills if they expect to advance
their career. I was not sensitive to criticism.  Over sensitivity can also
have drawbacks.