know from

[Laurence Horn]

At 2:01 AM -0700 12/27/02, Rudolph C Troike wrote:
>I am familiar with the locution from at least the 40s, in South Texas,
>almost always used somewhat jocularly in the deliberately informal "-g
>dropping" pronunciation of "nothing" in the fixed phrase: "He don't know
>from nothin'". The only likelihood of Yiddish influence in South Texas
>would be via radio programs (Fibber McGee & Molly, Jack Benny, etc.) The
>collocation can be a condensation of "He doesn't know X from Y" (X =
>anything, Y = a hole in the ground, etc.).
>
Two problems with this:
1) You'd expect "know from" to be a negative polarity item like "know
X from Y", but it's not.
2) You'd expect "know from" to show up in areas without direct
Yiddish/German influence, since the negative polarity "know X from Y"
is not regionally restricted, but it doesn't.
3) You'd expect "He doesn't know from a hole in the ground" (or what
I assume is the unexpurgated version, "He doesn't know from a hole in
his ass")  to represent the original version, and I suspect this
doesn't occur at all.  These expressions (cf. also "He doesn't know
shit from shinola") allude to imperfections in the referent's powers
of discernment, not in his or her general knowledge about a
particular entity or field.  "know from" in the sense of 'know about'
is quite different.

I'm prepared to agree that the source may well be German and/or
Yiddish "von" translated as 'from' rather than the more appropriate
'about', and that "doesn't know from nothing" may have been a crucial
step on the way, but I don't think "He doesn't know X from Y" was
involved.

Larry