After the English (Collin) and German (Peter) soldiers meet in no-man's-land, Collin tries to compliment Peter's English:
Collin: You speak good English.
Peter: I speak English well.
From the same scene, after a coin flip: "I see the face of my Kaiser. He is not pleased with me right now."
Also, the response Peter gets when he asks for more wire cutters.
In the play version, they don't even speak a common language, so they stumble and pantomime through the scene, which is capped off with the allied soldier proclaiming (quite passionately) that: "There would be a lot less cryin' widows in the world if blokes would just talk to each other like you and I have!" The german soldier is very confused, and simply extends his hand and gives his name as Manfred. To which the allied soldier responds: "Same to you!"
The comparison between Italian food and Italian women.
The goose trying to get in the house at every opportunity. And also chasing the Landlord out the gate.
The English and Germans in their respective trenches - both sides trying to call Joey to them before they realize he is tangled up in barbed wire.
English soldier: How do you call a horse?
Another English soldier: *begins clicking his teeth*
Entire English line: *begin clicking their teeth*
German soldiers: *look at each other in confusion*
Entire German line: *begin whistling*
Albert trying to impress a pretty girl riding in the car driven by his landlord's son. He and Joey manage to outrace them but when Albert tries to get him to jump over a stone wall, Joey stops short and Albert falls off. He looks up at Joey and says resignedly "Well you're clearly not going to be a jumper."
Lt. Waverly being proud of his new silk cap:
Lt. Waverly:(admiring himself in the mirror) Silk lining. I quite like it.
Cpt. Nicholls: I'm not sure it's going to make a lot of difference to the Germans.
Waverly: Oh, I don't know about that. Think about it. You're a Boche, just working out which of two chaps to shoot and you thought - "Good Lord - one of them really is wearing a very stylish cap indeed!" You might shoot the other one instead.
Nicholls: Or, alternatively, think - "I fancy that cap" and kill you first of all. (Waverly removes his cap)