One of the purposes for using present simple is to speak about facts:
E.g. "She lives in London" ... here I know 100% that she lives there, so I use present simple grammar and I add "s" to the verb when I speak about "he, she, it"
But when I use the word "think" or "maybe", should I still use the present simple grammar, because in this case I am not sure 100% that she lives in London? There is doubt about where she lives.
Should I say "I think she lives in London", or "I think she live in London"?
Second question related to the first one:
Is the using of present simple only for telling facts, or can I use it in telling fictional story or imaginary situation?