(I) can't say's I do

(I) can't say's I do

I don't know with certainty. ("Say's" is a colloquial contraction of "say as.") A: "Do you know how many people are coming to dinner tonight?" B: "Hmm, can't say's I do." They asked me if I know how to create a spreadsheet like that, but I can't say's I do.
Farlex Dictionary of Idioms.
See also:
  • (I) can't say as I do
  • can't say as I do
  • (I) can't say as I do(, can't say as I don't)
  • as we know it
  • AFAIK
  • as you know
  • a closed book
  • closed book, a
  • I know
  • know where it's at