can

\ \ [OE] English has two distinct words can. The verb ‘be able to’ goes back via Old English cunnan and Germanic *kunnan to an Indo- European base *gn-, which also produced know.

\ \ The underlying etymological meaning of can is thus ‘know’ or more specifically ‘come to know’, which survived in English until comparatively recently (in Ben Jonson’s The Magnetick Lady 1632, for example, we find ‘She could the Bible in the holy tongue’). This developed into ‘know how to do something’, from which we get the current ‘be able to do something’. The past tense could comes ultimately from prehistoric Germanic *kuntha, via Old English cūthe (related to English uncouth) and late Middle English coude; the l is a 16th-century intrusion, based on the model of should and would. (Canny [16] is probably a derivative of the verb can, mirroring a much earlier but parallel formation cunning.) Can ‘container’ appears to come from a prehistoric Germanic *kannōn-.

\ \ Cf.⇒ CANNY, CUNNING, KEN, KNOW, UNCOUTH