There are two ways in Korean to form negation. ‘안’ and ‘-지 않아요’ are both used to make a negation. The easiest way is to just put the adverb ‘안‘ in front of verbs or adjectives. The second way to use the pattern ‘-지 않다‘. This pattern directly follows by verbs or adjectives. So, negation formed by ‘안‘ is called ‘short type negation’, and the Negation by ‘-지 않다‘ is ‘long type negation’. There is no difference in meaning between the form ‘안 + verb/adjective’ and the form ‘verb/adjective + –지 않아요‘. But, there are some restrictions in ‘short type negation’ 1. For 'noun + 하다' verbs use noun + 안 + 하다 영희는 오늘 종일 공부하지 않았지?(O) 영희는 오늘 종일 안 공부했지?(X) 영희는 오늘 종일 공부 안 했지?(O) 2. Some verbs which have their own special negative counterparts(모르다,알다, 있다, 없다) cannot used with ‘short type negation’ 그는 그 일에 대하여 모르지 않았다.(O) 그는 그 일에 대하여 안 몰랐다.(X) 3. Long syllable verbs(아름답다, 울퉁불퉁하다, 화려하다,사랑스럽다,좀스럽다) cannot used with ‘short type negation’ 꽃이 아름답지 아니하다.(O) 꽃이 안 아름답다.(X)

가지 않아요 is the traditional Korean and the proper one while 안 가요 is the new one due to the wesern influence. Think of it as: "It deson't exist" vs "It's non-existent" =================================================== EDIT: ~지 않다 breakdown 가다 conjugates to the 가지, and becomes a "noun" 않다 is an abbreviation of 안 하다 ==> noun(go) not do

~지 않다 is more formal than 안