might/should have known

: past tense ofmay

: used in auxiliary function to express permission, liberty, probability, possibility in the past or a present condition contrary to fact or less probability or possibility than may or as a polite alternative to may or to ought or should

:  the power, authority, or resources wielded (as by an individual or group)

:  bodily strength

:  the power, energy, or intensity of which one is capable

: past tense ofshall

: used in auxiliary function to express condition

: used in auxiliary function to express obligation, propriety, or expediency

:  generally recognized