No, I don't know German.
The Big Bang Theory Season 2, Episode 3
You know,
the German philosopher,
The Big Bang Theory Season 5, Episode 7
Unless they're German,
The Big Bang Theory Season 7, Episode 12
Like reenacting the ancient German practice
of trial by combat.
The Big Bang Theory Season 8, Episode 19
Now, in German.
The Big Bang Theory Season 10, Episode 20