Praise with the wrong melody
Sarcasm says something positive and means the opposite. The words are praise; the melody contradicts them. Genuine enthusiasm in German jumps up high and falls steeply. Sarcasm uses the same words with almost no movement: the voice starts low, stays flat and ends low.
Same word, two meanings
Super!
[SUper! ↗↘ high peak, quick, steep fall]
Great!
you really are pleased
Na … super.
[na … suuuper → low, flat, stretched]
Oh, great.
the train has just been cancelled
The words that tip it
English deadpan can do without any marker. German sarcasm often has one: na before the praise word, auch after a thank-you, ja inside the sentence, or a doubled ja, ja. These words make the sarcasm unmistakable even when the melody is weak, so you will hear them all the time.
Marker plus melody
Na toll.
[na tooll → flat, low]
Oh, brilliant.
Vielen Dank auch.
[vielen DANK auch ↘ heavy fall on Dank, auch low]
Thanks a lot.
the auch alone turns thanks into reproach
Das hast du ja prima hingekriegt.
[das hast du ja priiima hingekriegt → flat]
Well, you really did a great job there.
Ja, ja.
[JAja ↘ quick and falling: I don't believe you]
Yeah, right.
The same sentence, both ways
Herzlichen Glückwunsch
Herzlichen Glückwunsch!
[herzlichen GLÜCKwunsch! ↗↘ warm, wide range]
Congratulations!
a colleague has passed an exam
Herzlichen … Glückwunsch.
[herzlichen … glüüückwunsch → low and level]
Well, congratulations.
a colleague has just deleted the shared folder
Das ist ja wunderbar
Das ist ja wunderbar!
[das ist ja WUNderbar! ↗↘ high start]
That's wonderful!
ja here expresses surprise and delight
Das ist ja wunderbar.
[das ist ja wuuunderbar → low start, no peak]
Well, isn't that wonderful.
the same ja, now with a flat line
Without a voice
In a chat or an email the melody is gone, and only the marker words remain. Without them, Super, danke is usually read literally. Germans often flag sarcasm in writing explicitly, with quotation marks, an emoji or a dry Ironie aus.