Question

don't + ??? .i am not sure about that..

Answer 1

Answer:

When you say "I'm not sure", other people might think that you have the idea about something but you are uncertain how would you validate or verify it.

When you say "I don't know", other people might think that you don't have the idea about something. Sometimes, saying this might raise ignorance to other people (directly or not) and saying this has more negative weight of aura towards others.