Klingon: tlhIngan Hol vIjatlhlaHbe' English: I Can't Speak Klingon.
Phonetically -- "TLi-ngan KHOL vi-JATL-lakh-BE "
The verb jatlh, meaning "speak," as used in a sentence. One would say this to indicate that the speaker does not know how to speak the Klingon language.