A similar question was answered recently, so I just copy that answer below. Essentially it turns a noun into a word, like -하다 which has a similar function. You can think of it like "-ish" or "-like" in English. **** Both -하다 and -스럽다 attaches to a noun to turn it into an adjective. -하다 appears more in the older, long established words, whereas -스럽다 tends to be used with more recent words or new coinage. It is difficult to know which one to use with a given noun, or whether or not both can be used. The best way is to check a lot of examples and familiarize yourself to the expressions. 사랑스럽다: lovely, lovable; 사랑하다 means "love you", an entirely different meaning. 자연스럽다. natural (자연: nature). 자연하다 is never used. 촌스럽다. boorish (lacks refinement; 촌: backwoods country), 촌하다 is never used. 뻔뻔스럽다. thick skinned, unscrupulous. 뻔뻔하다 is also widely used. 수다스럽다. talkative (수다 means excessive talk). 수다하다 is not used. 억척스럽다. tough and tenacious. 억척하다 is not used. 상냥하다. nice and sweet. 상냥스럽다 is not used 용감하다. brave. 용감스럽다 is not used. 용맹하다. brave and fierce. 용맹스럽다 is also used.