Persian
From The Big Bang Theory Wiki
Language widely spoken in Iran, Afghanistan, Tajikistan, Uzbekistan and Bahrain. One of the local names is Farsi.
A language that Sheldon says Howard can speak, at least when flirting with girls (0101):
Sheldon: Oh, right, yes. I could have stayed behind and watched Wolowitz try to hit on Penny in Russian, Arabic and Farsi.
