To do well at something you tried to do
succeed
To be unsuccessful at something
fail
Making you feel annoyed and upset when you are prevented from achieving something
frustrating
To make something better
improve
Not confident about yourself
insecure
Believing that you can do something well.
confident
Make an action or a decision that is not correct, or that produces a result that you did not want.
Make mistakes
Bad or harmful.
Negative
Good or useful.
Positive
