können

ser capaz

The more basic phenomenon (of understanding) is competence, capability (This interpretive thesis is prominent in the literature. See, for example, Dreyfus (1991), Guignon (1983), and Schmitt (1969)):

In ontical discourse (ontischer Rede) we often use the expression “to understand something” (etwas Verstehen) to mean “to be able to manage a thing” (einer Sache vorstehen können), “to be equal to it” (ihr gewachsen sein), “to be capable of something” (etwas können). In understanding (Verstehen), as an existentiale, that of which one is capable is not a What (Was), but rather being as existing (Sein als Existieren). (SZ:143) (BHTI:33)