When “guess” is used to mean something like “think”, it indicates a lack of confidence in one’s answer, while “think” indicates a higher level of confidence. Example: A: “Who is your favorite singer? B: Adele, I guess. But I don’t know for sure. Patsy Cline is great too.” Compare this to: A: “Who is your favorite singer? B: “Definitely Adele. I think she has the best vocal range and the most nuance.” Another example: A. Do you want to go to the movies? B. I guess. Here, “guess” indicates a lack of enthusiasm.

I think that you like to watch to much tv. I guess that you like to watch to much tv. the words can sometimes be used interchangeably but in general guess means to somewhat randomly guess the answer to a question, while think means to think something through to arrive at an answer.

You would use "guess" when you're not sure about an answer in any way. You would use "think" in a similar way if you've tried to figure out the answer, but you're not confident.

Good question! Actually, they are quite different. When you guess something that you aren't sure about, you say 'I think...' 'I think it's ok.... but I'm not really sure..' or 'I don't remember exactly but I think...' (but "I think.." also can mean 'in my opinion..'!) When you realise that something is probably true, and accept it (unhappily), you say 'I guess..' 'I guess it's ok... we can't find anything better' or 'I'll have to do it again I guess..' :)