Expressing optimism.

I’m sure it will work well. 

I’m very optimistic.

I’m positive about it.

This is bound to be successful.

Things will work out all right.

I don’t see how this new scheme can fail.

I have every confidence in this policy.

I feel quite sure that the sales will increase next month.

I anticipate success in this coming trade expo.

Expressing pessimism.

I doubt we can adopt the new system

I’m not sure it will be easy to apply.

I’m still rather doubtful about it.

I’m fairly pessimistic about its implementation.

I don’t hold much hope for that.

Our superior is bound not to agree to the idea.

I have to say I’m not all that optimistic about it.

There’s a slim chance that it can be done.

Can’t be done.

Fat chance!