Thanks a lot for this answer. Pls let me check again.
I was taught by an English teacher long time ago that "think (that)" was never followed by "negative sentence". Can we make sentences like " I think that he isn't polite"? Is this way of speaking used so often? That makes the person hurt though.
と、いうことでしょうか?
The other words such as "suppose" are used the same way as "think" above. However, as far as "guess" you seldom see "cannot guess 〜". Therefore, I had better take "guess (that) + negative sentence" rather than " don't guess (that) + positive sentence" Is it right?
I seem to be confused a little.
I am svery sorry if I might have been short of my words on my question.