He may be a star down South, but Prithviraj is facing some trouble with his very first film in Bollywood. The Kerala-based star who is making his debut opposite Rani Mukerji in Aiyaa is apparently finding is difficult to learn his Hindi lines considering the actor is not too familiar with the language.

Says a source, "Prithvi is fluent in his mother tongue Tamil and of course English, but Hindi doesn't really come naturally to him. The script isn't too tough, considering the language is very colloquial, but yet there are times when he has to sit down for hours together to get the lines right."

This apparently has resulted in the director taking out special rehearsal time for the actor.

Adds the source, "Prithvi wants to get it absolutely right and he does not want to compromise on the language. Though it is yet to be decided if his voice would be dubbed or not, he is giving it his best."

Interestingly we hear that co-star Rani has been patient and is helping him out too.

"Rani makes fun of him and his accent sometimes. They have become quite friendly though."

This undoubtedly is a dream entry for the star into the world of Hindi cinema, considering not many South actors apart from Rajnikanth, Kamal Haasan, Mohanlal and Madhavan have made it big in the Hindi cinema space.

Adds the source, "When Prithviraj got this offer there was no reason for him to refuse. He was being cast opposite Rani Mukerji and he has been planning to make the move from the South to Bollywood since a long time. So he is trying very hard to fit in."