이해가 안 돼요.

The phrase is composed of '이해하다' (to understand) and '안 되다' (to not work/to not be possible), with '요' being a polite ending. The direct translation of '이해하다' is derived from Sino-Korean roots: '이' (理) meaning 'reason' or 'principle', and '해' (解) meaning 'to solve' or 'to explain'. '안 되다' is a native Korean expression indicating negation or impossibility. The combined meaning thus conveys 'understanding does not happen' or 'it is not understandable'. This construction is typical in Korean for expressing states of being or conditions that are not met. While the individual components have etymological histories that could be traced back, the phrase itself is a standard grammatical construction in modern Korean. There isn't a specific '200+ words origin history' for this common phrase; rather, its etymology is understood through the origins of its constituent parts and their grammatical combination.