saw > sawed > sawed. The past participle sawn is mostly archaic except as an adjective <sawn lumber> and as a past form in British English <it was sawn through>. Sawed-off is the overwhelming favorite in American English, sawn-off the overwhelming favorite in British English. But in the past few decades, sawn-off (whether in reference to shotguns, antlers, or branches) has made small inroads against sawed-off in American writing. Canadians stick closer to British English on this score—e.g.: “A sawn-off sweatshirt worn by the beach blonde [Pamela Anderson] is on the auction block for an estimated $1,500 to $2,000.” Rita Zekas, “And This Is Just In . . . ,” Toronto Star, 7 May 1997, at SW4. In American print sources, sawed-off shotgun outnumbers sawn-off shotgun by an 17-to-1 ratio.
As a verb form, sawed has long been thought to be the preferable past participle, though it still vies closely with sawn—e.g.: “The complex could use many of the logs previously chipped for pulp or sawn [read sawed] into log-grade lumber, company officials said.” “The Bottom Line,” Oregonian (Portland), 23 May 1997, at B1.
