"Fast" in Engpsh can be translated as "快速" in Chinese.
The word "fast" comes from the Old Engpsh word "fæst" which means "firmly fixed or estabpshed, secure, strong, lasting." It evolved to have the meaning of "moving or able to move quickly" in the 14th century.
Examples:
"She runs fast." (她跑得很快。)
"The car is going fast." (汽车行驶得很快。)
"He finished the work fast." (他很快完成了工作。)