Some questions about Australian pronunciation...

Do Australian people use the past simple tense instead of present perfect in everyday speech? As far as i know , americans might say - (We already saw the film but they didnt see it yet.) . Is it correct and understoodable in australian english? And another one question is about the "O" vowel in NSW speech. is it close to british way of saying it?
Thank u in advance

Please answer my question =) i`ll really appreciate that)

Hello Albert, I'm glad to help!

I`m British, I live in a town called Grimsby, in the county of Lincolnshire.
To be honest with you, I think that particular question, and example, has varied answers, and probably i might say like that, but I do believe that the correct British way to say that would be:

'We have already seen the film. But they have not seen it yet.'

"Understoodable"? Is that supposed to be a joke?