"I think it’s really too soon for me to judge what kind of an actress Sonam is. I’ll have to work with her and then probably I’ll know better," the 28-year-old said here at the Radio Mirchi Music awards.
"Right now, as far as I am concerned, she has a very expressive face and I am sure she is capable of much more than she has already done," he added.
In "Raanjhanaa", both Dhanush and Sonam are from Varanasi and they study in Delhi.
Meanwhile, the "Kolaveri Di" man had composed a Sachin Tendulkar anthem and says it feels great now that he has got his 100th international century.
"There is nothing new that I can say about the Master. The song was aired a month ago and it has got 5 million clicks. Now that he has also got his 100th ton, it’s really great," said Dhanush.
Dhanush is currently in Mumbai working on the dubbing of the Hindi version of his wife Aishwarya Rajinikanth’s directorial debut "3".