unconfident

adj.缺乏信心的；不确信的

You are still unconfident with your speaking? 你还是为你的口语自卑吗？

I am always a people who is unconfident. 这样是不行的，我要对自己说加油。

I have been unconfident in whether this matter can be accomplished. 这件事情能不能办成，我心里一直没底。

Most of people will feel bashful and unconfident in the social activities. 大多数人，不同程度地会在社交活动中感到不好意思，没有自信。

I am unconfident about myself,because I am unable to understand your thought. 我对我自己没有信心。连你的想法都没法了解。