If we just decide to sing it like modern, standard German in the interest of keeping the songs alive, then you would sing:

Tsvy Ooksen, tsvy Ay-zel, oon enn grum-boock-li[x]- eh Koo.

dess gaybe meer my Fahter vahn i[x] high-rah-ten doo.
Pahr Hinkel oon enn Hahn-a, dess dooter air dah-tsoo.
[repeat line 2)

Notes: Tsvyrhymes with try. [x] is German ch as in "Ich" it is like the ch in Scots "Loch" only closer to the front of the mouth.

The oo in Ooksen, dooter, oon and grumbookliche is the short oo as in our word book.

The oo in Koo, doo, and dah-tsoo is our long oo as in "moon."

Zway Uxen, zway Esel, un en grumbuckliche Kuh
Des gebt mir mei Vatter wann ich heiraten du.
Par Hinkel un en Hawna, des dutter er dazu.
Des gebt mir mei Vatter wann ich heiraten du.
-------------------


Schlof, Bobbeli, schlof

Schlof, Bobbeli, schlof!
Der Dadi hiet die schof.
Die Mammi hiet die kleine Kieh,
In dem Wisse, kiehl un grie.
Schlof, Bobbeli, schlof.

Schloaf, Bob-bell-ee, schloaf
dair Dah-dee heet dee schoaf
dee Mah-mee heet dee kleine Kee
in dame vis-seh, keel oon gree
(repeat line one)

One last thing. When speaking German, speak at the front of your mouth, as certain British people do. It makes the sound crisper. You might trill the r's. If you sing this and anyone tells you you are doing it wrong, just claim it came from a different community. For example, if the complainer is from Pennsylvania, say you learned it in Iowa.

If I skipped something in the song, and I probably did, let me know.