In a conjoined sentence with connective ending ‘-으러’, one can find a movement of place from antecedent clause, and the purpose of the movement from following clause. Therefore, a verbal constraint is formed that only strong action verb, excluding the verb that shows the movement of place can be used in antecedent clause, and only motion verb can be used in following clause. The subject for antecedent clause can be 1st, 2nd and 3rd person, and there also forms a subject constraint that verbs in antecedent and following clause must agree. For the mood of following cluase, all of the moods such as declarative, interrogative, imperative, optative, commissive and etc can be used. Although negative expression cannot be used in antecedent clause, it can be used as ‘안(ahn)`` negative, ‘못(mot)`` negative, and also ‘말다(mal da)`` negative in following clause. However, when used as rhetorical questions, it shows verbalㆍsemantic characteristics that are different from ‘-으러’ that shows the purpose premise of a movement of place. Most significant characteristic is that a combination with not only motion verb but also general verb is possible since constraints of verb in following clause disappears. Unlike the facts that ‘-으러’, which shows purpose of movement of place can combine with almost all interrogatives, and strong action verb excluding motion verb can combine as antecedent clause verb without any particular constraints, there is constraints such as only ‘what+objective postposition`` can be combined among interrogatives, and only ‘하다(ha da)`` can be used as antecedent clause verb and can be used as fixed forms of ‘뭐/무얼/뭘/뭣.’Also, due to these vanishments of verbal constraints, meaning of movement of place is lost and meaning of ‘purpose`` is denied by rhetorical questions, and therefore, the meaning does not signify the purpose of movement of place but denial or restriction of possibility or necessity in accordance to different tenses or persons. In this case, verbal, semantic changes are emphasized, can be used as sentense concluding in a form of omitting following clause, signifies negative through function of rhetorical questions, but it is unlikely to be admitted as a complete grammaticalization since used as following clause can be restored. But it is identified to be different with when ‘-으러’, a connective ending that signifies purpose of movement of place, is used at the sentence concluding by omitting following clause, because an action verb other than motion verb can be used as the verb for the restored following clause. And it also functions as sentence concluding in a form of ‘뭐 하러’ without following clause. In this case, unlike when it serves its semantic function as denying necessity, it signifies euphamistic refusal. Therefore, unlike that preceding utterance is allowed with all moods except declarative and exclamatory when it signifies denial of necessity and functions as affirmative, volitive, and prohibitive, when used as final ending, previous utterance must signify suggestive, optative, commissive meaning and etc. Above all, the fact that restoration of following clause is impossible when ‘뭐 하러’ functions as following sentence could be the most significant proof that it cannot be defined as a connective ending that signifies purpose of movement of place. ‘-으러’ that serves to deny necessity, or functions to signify refusal to a suggestion or a demand, seems to be undergoing changes of its verbalㆍsemantic function on a process of becoming final ending from connective endings that signifies purposes through grammaticalization. These usage of ‘-으러’ is very active in actual use of language and should not be overlooked.