It seems that~ / I think that~ = - 것 같다. - 고 생각하다 can also be apply as 'It seems that~ / I think that~' but there are some times that cannot be applied. - 것 같다 is safer to use when you are using Korean sentences. * Grammar tip => In front of -것 같다, you need to put the 'adjective form' of Korean verb. Since '것' is a noun, the adjective form should be attached in front of '-것 같다.', to make the grammar structure make sense. So to answer your questions, it will be... 1. It seems to me that~ = 나는 ~ 것 같다 ex) It seems to me that it is too small -> 나는 이것이 너무 작은 것 같다. 2. I think that~ = 나는 ~ 것 같다. ex) I think that is too big -> 나는 그것이 너무 큰 것 같다. As you can see, it can be applied to both sentences naturally. : ) Hope it can be a help. : )