Yes. (answer to yes/no question) HIja' or HISlaH
No. (answer to yes/no question) ghobe'
Yes, OK, I'll do it. lu' or luq
No, don't, I won't. Qo'
Hello. (Roughly, "What do you want?") nuqneH
What's happening? qaStaH nuq?
I understand. jIyaj
I don't understand. jIyajbe'
Good! (expression of satisfaction) maj
Well done! majQa'
Where is the bathroom? nuqDaq 'oH puchpa''e'
Come in yI'el (to more than one person: pe'el)
Come here. HIghoS
Go away. naDevvo' yIghoS (to more than one person: naDevvo' peghoS)
Open the door! lojmIt yIpoSmoH! (See note if you think something is missing here.)
Don't be silly. yIDoghQo' (to more than one person: peDoghQo')
Your mother has a smooth forehead! Hab SoSlI' Quch! (Note: this is a powerful insult; don't say it to friends.)
Today is a good day to die. Heghlu'meH QaQ jajvam
We are Klingons! tlhIngan maH!
Happy birthday. qoSlIj DatIvjaj (to more than one person: qoSraj botIvjaj)
What time is it? 'arlogh Qoylu'pu'? (Literally, "How many times has it [presumably some traditional hour alarm] been heard?")
Shut up! bIjatlh 'e' yImev (to more than one person: Sujatlh 'e' yImev)
That's great news! buy' ngop (Literally, "The plates are full")