I think - ~고 생각해 (Opinion) | Learn Korean: LP's Korean Language Learning

I think - ~고 생각해 (Opinion)

고 생각해 is usually used when you are expressing your opinion on something like what people should and shouldn't do and what people should and should not be allowed to do etc.

Refer to Have to - 해야 한다, Allowed to - 해도 된다 and I like doing - 하는게 좋다, 하는걸 좋아한다 to learn following examples.

Rules

Attach 고 생각해 to the present informal written form of verbs.
eg.

그걸 해야 한다고 생각해 = I think we should do it.
공원엔 가도 된다고 생각해 = I think it's OK to go to a park.
우유를 마시는게 좋다고 생각한다 = I think it's good to drink milk

Note: 그걸 = 그것을, 공원엔 = 공원에는

Example sentences

저녁에 일찍 자고 아침에 일찍 일어나야 된다고 생각해.= I think people should go to bed early at night and get up early in the morning.
건강해지기 위해 과일과 채소를 많이 먹어야 한다고 생각해. = I think people should eat a lot of fruits and vegetables to become healthy.
TV는 많이 봐도 된다고 생각해요 = I think it's allowable to watch a lot of TV.
시간약속에 늦으면 안된다고 생각합니다 = I think it's not acceptable to be late for an appointment
책은 많이 읽는게 좋다고 생각한다 = I think it's good to read a lot of books.
청량음료는 많이 마시지 않는게 좋다고 생각합니다 = I think it's not good to drink a lot of soft drinks.

4 comments:

Anonymous2:43 AM, July 02, 2009
Thanks for another useful post!

This sentence pattern can only be used to express what I think, right? What do I do if I want to say what someone else thinks? Would I use the -다고 같대 pattern? Or can I do something like this:

친구의 생각에는, 제가 과일 을 많이 먹어야해.

(I'm trying to say, "My friend thinks that I should eat more/a lot of fruit." A more literal translation might be, "In my friend's opinion, I should eat more/a lot of fruit.")

I'm not sure, so please correct my mistakes! Thank you in advance!
Luke9:59 AM, July 02, 2009
When talking about a third person's opinion, 다 changes to 대, and 대 is a contracted form of 다고 해.

For eg.
have to go = 가야 한다고 해 = 가야 한대.

or

가야 된다고 해 = 가야 된대

가야 된대 is more commonly used than 가야 한대 in spoken Korean.

Have to - 해야 한대/된대
Allowed to - 해도 된대
They/he/she like(s) doing or It's good to - 하는게 좋대

친구가 나는 과일을 많이 먹어야 된대. = My friend (thinks/told me) that I should eat a lot of fruit.

체육선생님이 운동 많이 하는게 좋대. = The P. E. teacher (thinks/told me) that it's good to do a lot of physical exercise.

[BTW 체육선생님은 운동 많이 하는게 좋으시대 = The P. E. teacher likes doing a lot of exercise.][좋으시대 is an honorific form of 좋대]

Like what you did in your example, you can add 친구의 생각에는.

친구 생각엔 내가 과일을 많이 먹어야 된대.

I've also noticed that your sentence contained both formal and informal forms. 제가 is formal and 먹어야해 is informal. Watch these out! It is very easy to mix them up, I know.

친구가 나는 과일을 많이 먹어야 된대. or

친구가 저는 과일을 많이 먹어야 된대요.

Thank you again for bringing it up! It makes me to think about subtle grammar points!
Anonymous12:36 PM, July 02, 2009
Thank you so much! I couldn't find this anywhere! Yes, I need to watch out for the formal and informal forms. Actually, I originally typed "요" at the end of my example sentence, but I must have erased it by mystake before publishing my comment. Oops!
Anonymous12:57 PM, October 06, 2017
this lesson could explain more on how to use "I think - ~고 생각해".