i am/be not sure

I'm not sure about the bagpipes, though.

I'm not sure what to think.

I'm not sure if I got it right.

I'm not sure if I'm going to be comfortable with this, but we'll give it a run, okay?

My heart still racing I wasn't sure what to do and kept seated.

I'm not sure that in my lifetime there's going to be a magic potion that suddenly will take all the pain away.

I'm not sure there's anyone who's sensible enough to do the first bits of that, and unhinged enough to do the last part.

Man, the books are so good, but I'm not sure that I want to like give more away.

At the moment I am following an exercise routine and I'm eating healthily, but I'm not sure if it's having much effect.

Although, honestly, I'm not sure how you sign off on a letter asking-- where you're asking someone to prove that they're not dead.

I was not sure if it would have some restrictions or if there's some things that it wouldn't let you do, and it turns out I haven't been able to find any so far.