In the German tongue, in the Polish town Scraped flat by the roller Of wars, wars, wars.
Now we get more about Germany than just an exclamation in the language. The speaker is talking about the German tongue, or language, but in a Polish town that has been destroyed by war.
But the speaker doesn't just say something like "destroyed by war" – she says it has been "scraped flat by the roller of wars," which makes us think a bulldozer and also of rolling out cookie dough until it's flat.
Then, she repeats the word "wars" three times, giving us the idea that this place has been flattened by more than one war.
But the name of the town is common. My Polack friend
Says there are a dozen or two. So I never could tell where you Put your foot, your root,
Now we find out more about this town – its name is common. The speaker's Polish friend says there are a bunch of town in Poland with the same name.
Because there are so many towns with the same name, the speaker will never know where "you," her father, has "put [his] foot, [his] root" – this probably means that she is wondering where he immigrated from, but will never be able to tell.
I never could talk to you. The tongue stuck in my jaw.
It stuck in a barb wire snare. Ich, ich, ich, ich, I could hardly speak.
The speaker also laments that she could never talk to her father, because her tongue always stuck.
Even worse, the area where her tongue got stuck was like a barb wire snare. Barbed wire is pretty nasty stuff, and would rip a tongue to shreds.
The speaker demonstrates her tongue getting stuck in German, repeating "Ich," the German word for "I." Her tongue seems to get stuck so badly that she can only stammer, "I, I, I…"
Why did her tongue stick? We're not sure. Maybe her father made her nervous or scared. Maybe she's not very good at speaking German. What do you think?
She then repeats that she could hardly speak, but the context of this line seems to be more general – earlier, she said she could hardly talk to her father but, now, she can hardly speak at all.
I thought every German was you. And the language obscene
Our tongue-tied speaker is telling us that she thought every German was her father, and that she found his language dirty and offensive.
Maybe her tongue only got stuck when speaking German. Perhaps she got nervous speaking the language of her father to other Germans, who all seemed like her father.
These lines show us that the speaker is deeply disturbed by memories of her father. She sees him in every German person she comes across, and the association is unfortunately a negative one.