The cast of Broadway's Relatively Speaking — the collection of three one-act comedies written separately by Woody Allen, Ethan Coen and Elaine May — only hinted at details of plot and character while still in rehearsals under the direction of John Turturro. At a Sardi's press reception, some clues are dropped by troupers Bill Army, Julie Kavner, Caroline Aaron, Ari Graynor, Patricia O'Connell, Mark Linn-Baker, Marlo Thomas, Fred Melamed, Steve Guttenberg, Katherine Borowitz and Grant Shaud. Expect the "conflict of selfishness and love," in the context of mothers and daughters, husbands and wives, parents and children. You know — relatives. Previews begin Sept. 20 at the Brooks Atkinson Theatre.