
If I give the right command in German,
she'll rip your face off.
The Big Bang Theory Season 6, Episode 21

Quartz, from the
German "quarz"
The Big Bang Theory Season 12, Episode 2

Now, in German.
The Big Bang Theory Season 10, Episode 20

Unless they're German,
The Big Bang Theory Season 7, Episode 12

...and I could smell German chocolate cake,
which is my favorite.
The Big Bang Theory Season 1, Episode 16