込(こ)む ②Remain, To do thoroughly, Deeply, Intensely

Both can attach to verbs to form compound words. 切る emphasizes full completion or decisiveness, e.g. '言い切る' ('say definitively') or '読み切る' ('finish reading'), focusing on doing something thoroughly to its end. 込む conveys depth or intensity of action, e.g. '考え込む' ('get lost in thought'), highlighting depth rather than finality.

込む can be added to verb stems to express two nuances. The first is inward or inserted movement, as in 放り込む ('throw in') or 読み込む ('read in', such as reading data into a computer). The second suggests intensity, depth, or duration of an action, as in 考え込む ('think deeply') or 座り込む ('sit down and refuse to move').

Both 込む and おわる attach to verb stems but express different nuances. おわる simply marks the end of an action, e.g. ケーキを食べおわった ('I finished eating the cake.') or 映画を観おわった ('I finished watching a movie.'). 込む adds the sense of doing something thoroughly and staying in that state, e.g. 黙り込んだ ('He fell completely silent and stayed that way.').