|1.||I think so|
A way of saying that you don't know but want to make it look like you might know. Similar to saying "I'm pretty sure," but could also mean "I'm not totally sure."
Soldad: Did you do your homework?
Sonia: I think so.
Jeff: Is the final tomorrow?
Lola: I think so.
Chris: Do you understand the words that are coming out of my mouth?!
Jackie: I think so.
Chris: Is that a yes or a no?