In a short film it is quite likely that there will be very little dialogue. There might only be a line or two - or even nothing! It is quite common to be asked to improvise a scene - though they may just chat to you and ask you to read from a script.
Was there some kind of character description in the breakdown?
I always ask if I can see the screenplay beforehand if it's a short film. The answer has always been yes, but I suppose they are quite within their rights not to send it (seems daft to me not to, mind). If they give you the script (i.e. your lines) at the audition, make sure you have time to read it through. You might only need a minute or two, but make sure you get them. It is fine to be assertive. Wherever possible, look up from the script
especially where the character is listening to others speaking - this (in my opinion) is where people score or otherwise in a filmed audition. It's usually much more about your truthful reactions than the way you deliver lines. You will have the chance to ask THEM about the character. Showing an interest in their vision for the film always goes down well
They will have presumably chosen you for audition because they like your photo and maybe your CV so take confidence from that - you're already half way there! Be friendly and honest and be yourself. That's who they want to see!
I do wish people would give more idea about what to expect though and how they plan to run the auditions - it's not much to ask.
Good luck!
that would help
