A little help please

I have a friend who is Japanese and she plays tennis. I notice that she often says things to herself when she plays and most of the time, by her expression and when she says it, I can guess what she is saying. I was just wondering if someone could take the time to translate a few phrases that I think she might be saying. Thanks a lot.

(She is saying all these phrases to herself.)

Damn it!
What are you doing?
Hit the ball up!
Stay in! or Get down!(refering to ball staying in court...I think she says this a lot.)
Come on!

If anyone can think of other phrases one might say while playing such a sport, I would GREATLY appreciate some translations. Thanks again!

I think it might be better if you wrote out the sounds that you hear (she is talking in Japanese, right?) - because when it comes to cursing and such emotional expressions, the degree/tone can be quite different between Japanese and English...

Oh, well I can't remember exactly what she says in Japanese but I know if I read them then I will recognize it. I hope that makes sense. She is saying all these with frustration, I guess like when the game gets really heated. It is okay if I can't get translations. I was just curious.

To James,
Well, I just felt that... if would be fairer to your friend that way lol. Noone really says something as strong as "damn it!" during a tennis match in Japanese, that I just didn't want to give the closest expression that I could come up and you taking it as the exact equivalent :) Also, I imagine that people would say more of self-encouraging words...

"Stay in!" or "Get down" (referring to the ball) would be "Haire!" (literally: get in!) or "Nokore!" (literally: stay in!)
"What are you/am I doing?!" = "Nani shiteru no!" "Nani shiten no!"

Others I could think of are something like:
"Dame da!" = No good! (to oneself)
"Mada mada!" = I've gotta work myself harder!

Oh yes I recognize "nokore" and "dame da." Thanks a lot for the help! Sorry if I made it difficult for translations. ^^