Recent work on elliptical forms of the English imperative has drawn quite heavily upon the apparent parallel between tag formation in imperatives and tag formation in interrogatives. Thus, it has been argued that the auxiliary in imperatives must be will because in all interrogative tag formations the auxiliary element in the appended tag is the same as the one occurring in the initial segment (Klima, 1964: 254; Postal, 1966; Katz & Postal, 1964). The invited comparison is between tag-interrogatives like (1) John did it, didn't he? (2) They can do it, can't they? (3) He can't do that to us, can he? (4) You will try harder, won't you? and putative imperatives like (5) Do it now, will you! (6) Bring me a slab, won't you! (7) Bring me a slab, will you! (8) You will try harder, won't you! Consideration of such examples makes it fairly evident that, in the cases of the elliptical constructions (5)–(7) aux Will has been deleted from the initial segment and hence occurred in the deep structures serving as the sources for these constructions. Moreover, such parallels provide good motivation for the conjecture that ALL imperatives eventually derive from underlying sources whose phrasemarkers contain the element will (Postal, 1966: 162; Katz & Postal, 1964: 75). It is my purpose here to attempt an analysis of the putative parallel between tag-imperatives and tag-questions in order to determine the extent to which it supports such conjectures about the specific nature of structures underlying English imperatives.