New Delhi: Saif Ali Khan says playing a Dalit teacher in Prakash Jha's upcoming film 'Aarakshan' has been his most difficult role so far.

The actor, who has an image of the sophisticated urban hero, is seen speaking in chaste Hindi in the movie, which also stars veteran, Amitabh Bachchan, Deepika Padukone, Prateik and Manoj Bajpai.

And it was not an easy task for the actor, who struggles with Hindi in real life, to speak the language fluently, especially in front of Bachchan, who is famous for his command on the language.

"I am really happy to work in this movie and I thank Prakashji for giving me the most difficult and complicated role of my career. I have worked hard to understand and play this character," Saif, who was in the city to promote the film, told reporters.

The 40-year-old actor said that despite having reservation as the backdrop, the film talks about human relationships and how issues like this affect individual.

"I think it is a very dramatic movie. When I was offered the role, my mother told me 'Go practice your Hindi' and she was right. Prakashji and Amitji both speak the Sanskrit Hindi," Saif added.

Aarakshan' releases all over on August 12.