pidgin English and "Nix Forstay"

[Douglas G. Wilson]

> From the OED, under "nix" --
>
>    1866 CAPT. FLACK Prairie Hunter (1879) xxi. 98 When 'Nix-forstay' (a
> common nickname for the Germans in the far south-west) returned..he
> proceeded to rake the fire for his supper.

"Spigotty" is English, I suppose, i.e., "spik-a-de" = "speak the" ... for
something like "I [don't] speak the English".

But "nix-forstay" appears to be German, i.e., "nicht[s] versteh-". Why is
it not "forstay-nix" (= "[ich] verstehe nichts" = "[I] understand nothing"
or "[ich] verstehe nicht" = "[I] don't understand")?

Is the expression from a subordinate clause like "... weil ich nichts
verstehe" = "... because I don't understand anything"?

Or is it from a word like "Nichtsversteher" = "one who understands nothing"?

Or is "Nicht[s] verstehe" alone a conventional utterance in some form of
German?

Or is it pidgin-German with English word order, "nix" = "nicht" ("not") +
"forstay" ("understand")? [This interpretation seems likely to me, and it
is perhaps supported by a memoir of 1910:
http://www.lib.duke.edu/forest/Biltmore_Project/Esser30oct1910.pdf ]

[Maybe the answer is trivially obvious to anyone well-versed in German ...
but not to me.]

-- Doug Wilson