Tesla CEO Elon Musk has said that Twitter Inc may charge a slight fee for commercial and government users."Twitter will always be free for casual users, but maybe a slight cost for commercial/government users," Musk said in a tweet.Musk has been suggesting a series of changes to Twitter since last month. After adding the company to his cart recently, Musk said he wanted to enhance the platform with new features. In last week of April, Twitter confirmed the sale of the company to Elon Musk for USD 44 billion. Twitter CEO Parag Agrawal in his statement said "Twitter has a purpose and relevance that impacts the entire world. Deeply proud of our teams and inspired by the work that has never been more important."