Since breaking into movies at the age of 14 in Jean-Luc Godard's Détective, Julie Delpy has worked tirelessly as an actress, writer, director and producer. She's best known for roles in Krzysztof Kieslowski's acclaimed Three Colours trilogy (Blue, White and Red), Killing Zoe, Before Sunrise and TV series ER and was nominated for an Oscar for co-writing the screenplay for Richard Linklater's Before Sunset (2004). Two Days In Paris marks her second feature length film as writer, director and star. She tells BBC Movies about some of the challenges involved and throwing her male lead in at the deep end!

Q. Where did the idea come from?

A. I always wanted to write a story about a couple coming to that moment in their relationship where either they keep on going or it ends - to examine what makes people make the decision to keep on going.

It's much less romantic that the Before Sunset and Before Sunrise movies in that it's a little more real and a little ruder? Was that always the intention?

Yeah, it's much less romantic. Before Sunset is about expecting someone that you can't have and dreaming about someone, expectations and all. I like that film very much and it's a very romantic idea about romanticism and love. But this one is ruder and examines the hard times of making a relationship work - and sometimes not succeeding so well.

What appealed to you about Adam Goldberg as the male lead? You wrote the part with him in mind, didn't you?

Yes. I knew him for a long time and I always thought he'd be great as a lead - an offbeat romantic lead. But he'd never had that chance because maybe he's a different kind of personality and people didn't dare hire him to play a whole film. I wrote it for him because I felt he was really like the sad clown. First of all he's very funny, he has a very natural comedic talent even when he doesn't want to! But I think that's the secret to it - the sadder, more angrier he looks, the funnier he is. There were times he didn't even want to be funny and he just had that quality.

I gather he came into it almost directly from Deja Vu, so you didn't get much rehearsal time together...

He arrived 12 hours before the shoot, which was pretty tough. He was also a week late. We had to postpone the shoot a week. But I can't compete with a huge Hollywood film like Deja Vu so...

But did that help in perhaps making the relationship between the two of you a little more spontaneous?

Well, we definitely had very little time to practice! I'd met him in LA and gave him the script when we discussed about his character and different things. But then the minute I went to Europe he got taken up with Deja Vu and we barely exchanged emails during that time. I was a little worried actually.

But I had a confidence that he would show up and be fine, because Adam is great when he doesn't think too much. When he starts to over-analyse stuff it kind of stops him. So to just be thrown onto the set was great because his character is the fish out of water. I didn't even have time to translate some of the scenes for him, so I'd give him the script and there were all these scenes in French. He'd ask me to translate for him but I was directing and no one else spoke English. It was quite amusing at times.

How did you enjoy working with your parents? Was it ever daunting to have to direct them?

That was wonderful. They were amazing, they were always switched on and totally respected me as a director - apart from when I asked them to rehearse! My dad was like: "Oh, you're not going to bother us with rehearsals!" So, I didn't rehearse with anyone really before we started shooting... well except Alexia Landeau who plays my sister, because we wanted to build something, a relationship with a sister... because I don't have one.

I actually never thought I was directing my parents. The shoot was so hard and in an emergency state that I never even had the time to think: "Oh, is it tough to direct your parents?" I just did it without thinking.

You received an Academy Award nomination for your screenplay on Before Sunset. Has that helped to open doors for you?

A little bit but not that much - maybe because it was assumed that we were co-writing so it wasn't clear who wrote what. It's almost like people thought: "Oh, she's the only woman in a group of three writers so maybe she was just there, sitting on the couch being pretty or something..." [laughs] But I wrote the first draft and was very involved with the writing of that film.

Have you started work on The Countess (about a 17th century Hungarian countess who embarks on murder in the belief that bathing in the blood of virgins will preserve her beauty)?

Yes. We're currently preparing to do it. I'm going over costume design, set design and meeting designers and stuff. So it's very exciting. But it's a very big step for me and it's a very different film to Two Days In Paris. It's a drama, and it's interesting for me to be able to go from a comedy to a drama. I'd like to try as many different jobs and styles as possible.

Two Days In Paris opens in UK cinemas on Friday, 31st August 2007.