확실히 모르겠습니다.

The phrase is composed of several parts: - **확실히 (hwaksilhi)**: This is an adverb meaning 'certainly,' 'surely,' or 'definitely.' It comes from the Sino-Korean word 확실 (hwaksil), meaning 'certainty' or 'sureness.' The suffix -히 (-hi) turns adjectives into adverbs. - **모르겠습니다 (moreugesseumnida)**: This is the formal polite form of the verb 모르다 (moreuda), meaning 'to not know.' - **모르다 (moreuda)**: The base verb 'to not know.' - **-겠- (-get-)**: This is an honorific and prospective suffix often used to express intention, ability, or, in this context, polite uncertainty or a tentative statement. It can also imply 'I think I don't know' or 'I will not know.' - **-습니다 (-seumnida)**: This is a formal polite declarative ending used at the end of sentences. Combining these elements, '확실히 모르겠습니다' literally translates to something like 'I certainly do not know,' or 'I am not certain that I know.' The '확실히' emphasizes the degree of uncertainty. It's a very common and natural way to express not knowing something definitively in Korean.