What's a "negative pregnant"?

A negative pregnant is a denial pregnant with the admission of the substantial facts in the pleading responded to which are not squarely denied. It is in effect an admission of the averment it is directed to.[1]

A negative pregnant is a form of negative expression which carries with it an affirmation or at least an implication of some kind favorable to the adverse party. It is a denial pregnant with an admission of the substantial facts alleged in the pleading. Where a fact is alleged with qualifying or modifying language and the words of the allegation as so qualified or modified are literally denied, has been held that the qualifying circumstances alone are denied while the fact itself is admitted.[2]

While it is a denial in form, its substance actually has the effect of an admission because of a too literal denial of the allegation sought to be denied. This arises when the pleader merely repeats the allegations in a negative form. (Riano)

If an allegation is not specifically denied or the denial is a negative pregnant, the allegation is deemed admitted. Where a fact is alleged with some qualifying or modifying language, and the denial is conjunctive, a negative pregnant exists, and only the qualification or modification is denied, while the fact itself is admitted. A denial in the form of a negative pregnant is an ambiguous pleading, since it cannot be ascertained whether it is the fact or only the qualification that is intended to be denied. Profession of ignorance about a fact which is patently and necessarily within the pleader's knowledge, or means of knowing as ineffectual, is no denial at all.[3]

[1] Philamgen v. Sweet Lines, G.R. No. 87434, 1993.
[2] Republic vs. Sandiganbayan, et. al., G.R. No. 152154, July 15, 2003, cited in R Transport v. Ejandra, G.R. No. 148508, May 20, 2004.
[3] BaƱares v. Atty. Barican, 157 Phil. 134, 138 (1974); Galofa v. Nee Bon Sing, 130 Phil. 51, 54 (1968), citing Ison v. Ison, 115 SW 2d. 330, 272 Ky. 836 and 28 Words & Phrases 314; 41 Am. Jur. 429; Vergara, Sr. v. Judge Suelto, 240 Phil. 719, 730 (1987), citing Moran, Comments on the Rules, 1970 ed., Vol. 1, p. 335; J.P. & Sons, Inc. v. Lianga Industries, Inc., 139 Phil. 77, 83 (1969); Philippine Advertising Counsellors, Inc. v. Hon. Revilla, 152 Phil. 213, 222 (1973); Gutierrez v. Court of Appeals, 165 Phil. 752, 757 (1976).)