"Think Vulgar" is a song created especially for the stage musical production of Chitty Chitty Bang Bang. It was written by Robert and Richard Sherman in 2001 and premiered at the London Palladium on April 16, 2002. It was subsequently replaced by "Act English" a year later. The song is sung in a private moment when the Vulgarian spies determine their strategy of deceit by which they will obtain possession of Caractacus Potts' invention, the car, Chitty Chitty Bang Bang.
The concept for "Act English" was conceived by book writer Jeremy Sams and director Adrian Noble who felt that "Think Vulgar" was not moving the story along at a quick enough pace. Although there were creative differences among the parties, the parties remained friendly.