Inform
Middle English enforme, informe ‘give form or shape to’, also ‘form the mind of, teach’, from Old French enfourmer, from Latin informare ‘shape, fashion, describe’, from in- ‘into’ + forma ‘a form’.
wiktionary
From Middle English informen, enformen, borrowed from Old French enformer, informer(“to train, instruct, inform”), from Latin īnfōrmō(“to shape, form, train, instruct, educate”), from in-(“into”) + fōrma(“form, shape”), equivalent to in- + form.
Latin īnfōrmis
etymonline
inform (v.)
early 14c., "to train or instruct in some specific subject," from Old French informer, enformer "instruct, teach" (13c.) and directly from Latin informare "to shape, give form to, delineate," figuratively "train, instruct, educate," from in- "into" (from PIE root *en "in") + formare "to form, shape," from forma "form" (see form (n.)). In early use also enform until c. 1600. Sense of "report facts or news, communicate information to" first recorded late 14c. Related: Informed; informing.