I’m not sure if + (verb) denotes you are uncertain about particular thing.
Examples:
” I’m not sure if she will accept it. “
” I’m not sure if she will marry me. “
” I’m not sure if it will work. “
” I’m not sure if that is correct. “
” I’m not sure if I should marry her. “
” I’m not sure if he will receive it. “
” I’m not sure if she will go. “
” I’m not sure if he is right. “
” I’m not sure if they have pets. “
” I’m not sure if laptop will work. “
” I’m not sure if mobile will work. “
” I’m not sure if system will start. “
” I’m not sure if she is right for me. “
” I’m not sure if I can do it. “
” I’m not sure if he will permit me. “
” I’m not sure if they will hire me. “
” I’m not sure if I will be selected. “
” I’m not sure if she is ready. “
” I’m not sure if he has completed his assignment. “
” I’m not sure if she likes me. “
” I’m not sure if I can handle it. “
” I’m not sure if it will matter. “
” I’m not sure if he will get the job. “