, ▁on ▁the ▁basis ▁of ▁these ▁studies , ▁form ulated ▁ ▁the ▁so - called ▁Case ▁Theory . ▁ ▁La ws ▁of ▁anal ogy ▁K ury łow icz ' s ▁is ▁also ▁known ▁for ▁his ▁" S ix ▁La ws ▁of ▁Anal ogy " ▁that ▁have ▁been ▁widely ▁used ▁in ▁historical ▁lingu istics ▁to ▁understand ▁how ▁analog ical ▁gram mat ical ▁changes ▁work . ▁The ▁laws ▁consist ▁of ▁six ▁predict ive ▁statements ▁about ▁the ▁direction ▁of ▁analog ical ▁changes : ▁ ▁A ▁b ipart ite ▁marker ▁tends ▁to ▁replace ▁an ▁is of unction al ▁simple ▁marker . ▁ ▁The ▁direction ality ▁of ▁anal ogy ▁is ▁from ▁a ▁“ basic ” ▁form ▁to ▁a ▁“ sub ordinate ” ▁form ▁with ▁respect ▁to ▁their ▁spher es ▁of ▁usage . ▁ ▁A ▁structure ▁consisting ▁of ▁a ▁basic ▁and ▁a ▁sub ordinate ▁member ▁serves ▁as ▁a ▁foundation ▁for ▁a ▁basic ▁member ▁which ▁is ▁is of unction al ▁but ▁isolated . ▁ ▁When ▁the ▁old ▁( non - anal og ical ) ▁form ▁and ▁the ▁new ▁( anal og ical ) ▁form ▁are ▁both ▁in ▁use , ▁the ▁former ▁remains ▁in ▁secondary ▁function ▁and ▁the ▁latter ▁takes ▁the ▁basic ▁function . ▁ ▁A ▁more ▁marg inal ▁distinction ▁is ▁elimin ated ▁for ▁the ▁benefit ▁of ▁a ▁more ▁significant ▁distinction . ▁ ▁A ▁base ▁in ▁anal ogy ▁may ▁belong ▁to ▁a ▁prest ige ▁dialect ▁affect ing ▁the ▁form ▁of ▁a ▁dialect ▁im it ating ▁it . ▁ ▁Case ▁theory ▁In ▁this ▁theory ▁he ▁propos es ▁the ▁division ▁into ▁gram mat