I was wondering about speaking japanese...?

Question:

I am trying to figure another question out,when I am talking casually and saying
Watashi wa Brittney desu can I take off the desu and the Watashi wa?Or how does it work
I have seen japanese people talk without all the watashi,and anata and stuff,how much can I cut it down?
And what about desu.Do I have to say it everytime,like if if I said Mochiron to someones answer,do I have to add desu?When should I?

Answer:

Well, we often omit "Watashi wa" or "Anata wa".
But we don't omit "desu" so often. It is really rare. I think you'd better to think you can't omit them.

For example.
If someone asked you your name, you can say " Brittney desu". It is quite normal and polite.
But if you said "Brittney" only, it is a little rude.
You can say "Mochiron" to your friend with no problem. But if you said just "Mochiron" to your bosses, it might make them unpleasant.