(I) can't say that I do.
and (I) can't say's I do.; (I) can't say (as) I do.Fig. a vague response to a question about whether one remembers, knows about, likes, etc., something or someone. (The say as and say's are not standard English.) Jane: You remember Fred, don't you? John: Can't say as I do. Bob: This is a fine looking car. Do you like it? Bill: I can't say I do.