고지서를 받으�?송달지(실거주지)�?변경하실려�?서비스를 신청하여 주시�?바랍니다. The two commonest grammatical rules in which this happens is when conjugating in past times or current tenses. For examples: It really is incorrect to add any grammatical theory setting up by using a vowel, or with the option of adding a vowel, to 갖다. https://www.no1-anma.com/%EC%A4%91%EB%9E%91%EA%B5%AC%EC%B6%9C%EC%9E%A5%EB%A7%88%EC%82%AC%EC%A7%80