One of the more important forms to express conjecture and supposition in Korean grammar is the form -(으)ㄴ/는 것 같다. This form not only lets you express your supposition and conjecture. You can also use it to simply soften the way how you express your opinions or thoughts to others. The form itself is nothing special and easy to use.
One of the uses of the form -(으)ㄴ/는 것 같다 is to express your supposition and conjecture. You can use it for suppositions on the past, present and future. When you use this form it generally means “looks like”, “sounds like”, “appears”, “seems”, etc.
Another use of this form, however, is to express your thoughts or opinions in a more gentle or soft way or simply put a more polite way. This is a rather important use because in Korean culture there is a certain apprehension towards expressing opinions too direct. Therefore when you do express an opinion or your thoughts, it is best to do so with the form -(으)ㄴ/는 것 같다. A form that is far more direct is the form -어/아 보이다.
가: 김치찌개 맛이 어때요?
나: 조금 짠 것 같아요.
A: How is the taste of the kimchi jjigae?
B: It seems to be a little salty.
How To Use
Using the form -(으)ㄴ/는 것 같다 is not difficult even though a table of it might seem complex. However, in the end, it is nothing more than simply applying the ‘batchim/no batchim’ conjugation rule. Plus you already know all the rules if you already know how to use verbs and adjectives attributively in Korean. Therefore you needn’t worry too much about the conjugation rules. However, like always you still need to keep some irregular verb groups in mind such as the ㅂ irregular verbs. Also, do not forget to conjugate the verb 같다 that is part of the form!
Lastly, you can use the form -(으)ㄴ/는 것 같다 with verbs, adjectives and nouns. So you needn’t worry about what type of word you are dealing with.