Difference between と and とは


Difference between と and とは？

For example in below sentences

> そんなに大きいと思わなかった。

and

> そんなに大きいとは思わなかった。




_In this case,_ there is very little difference, although the latter strikes
me as a bit more common.

I would categorize the は in the latter sentence as a contrastive wa: "(I knew
it was big, but) I didn't think it was this big".

