Wiktionary
i don't think
interj. (non-gloss definition: used after a statement to indicate an emphatic or ironic negative)
Usage examples of "i don't think".
Even when I tell you how it was done, I don't think you'll really believe me.
She wasn't very receptive when I told her I was coming, but I don't think she'll slam the door on me when I land on her doorstep.
But I don't think there's anything in the rules mat says I can't take someone else along.
But I don't think she ought to have run away with Baedeker that morning in Santa Croce.