Present simple = forma de baza a verbului (think, believe, play, listen, etc). Luam ca exemplu "think" :
I think she's pretty.
Present continuous = verbul "to be" (cu formele "am"/ "are"/ "is") + forma de baza a unui verb+terminatia "ing". Ex si conjugari:
I am (sau I'm) thinking about her.
You are (sau you're) thinking about her.
He is (sau he's) thinking about her.
We are (we're) thinking about her.
You are (you're) thinking about her.
They are (they're) thinking about her.