What do these words/phrases mean in japanese?

Question

-Nani ko de - does this translate into something like "whats happening?"

-Koko de ma! - does this mean something like "I'm out of here"

-Shimatta

Answer 1

1. I think you mean "nani kore" (the R sound in Japanese is a bounce of the tongue off the roof of the mouth, it sometimes sounds like L or D).  It means "what is this?"

2. "koke de ma" is not a Japanese phrase.  Maybe you mean "koko demasu" = "I leave from here" but it is NOT used in the same way as English "I'm outta here"

3. "darn it"  (literally, "it is completely _____"

Answer 2

I'd just like to add, if you say "Nani kore" w attitude, it comes across as attitude, like if you go in your bedroom and your little brother has trashed it, you'd say, Nani kore? Or some gross guy gives you a note that says he likes you, you'd hold it between your index finger and thumb and say, Nani kore?!? In short, it's not polite and not something you say to people you don't know. For example, if your host mom put some Japanese food on your plate and you said that. . .she would be VERY angry. Although boys get away w saying that stuff more. . .boys are allowed to be more rude than girls in Japan!

So if you'd like to politely ask what something is when you honestly do not already know what it is, you'd say, Nan desu ka? Or, Kore wa nan desu ka?  

Answer 3

-Nani ko de

This is incorrect. If it's "nani kore", it means "What's this?"

-Koko de ma!

This is incorrect.

-Shimatta

This is like "OMG", shouting when you made a mistake.