Heath Ledger taught Julia Stiles how to act drunk in '10 Things I Hate About You'.

Heath Ledger

Heath Ledger

The 38-year-old actress - who played Kat Stratford in the 90s teen flick, which will celebrate its 20th anniversary this year - revealed that she had "never gotten drunk before" at the time of filming and the late actor, who portrayed her love interest, Patrick Verona, taught her "what that felt like".

Speaking to website Digital Spy, she said: "I had never gotten drunk before and I had to play drunk in one of the scenes. I remember Heath Ledger talking me through what that felt like!

"I look back on it so fondly. It's an honour to be part of a movie that people are still talking about 20 years later."

The film - which is loosely based on William Shakespeare's 'The Taming of the Shrew' - follows Cameron (Joseph Gordon-Levitt) who strikes a deal with bad boy Patrick (Ledger) to date 'shrewish' Kat (Stiles) so that her father will allow Cameron to date Kat's sister, Bianca (Larisa Oleynik).

The movie proved to be a breakthrough role for Stiles, Gordon-Levitt and Ledger - who tragically died in 2008, at the age of 28 - despite the film only receiving moderate box office success on original release in 1999.

The 'Riviera' star insisted that she was desperate for a role in the movie as it was the first time she'd read a script with "such a feisty teenage girl".

She said: "I wanted that part so badly; because it was the first time I had read such a feisty teenage girl. I hadn't seen a teenage girl like that on-screen."