The most common way to say "slow down" in Spanish is [ve más despacio](javascript:void(0)) for informal situations and [vaya más despacio](javascript:void(0)) for formal situations. Another common way to say it, especially in contexts like driving, is [reduce la velocidad](javascript:void(0)) (informal) or [reduzca la velocidad](javascript:void(0)) (formal). To politely ask someone to slow down their speech, you can say [¿Puedes hablar más despacio, por favor?](javascript:void(0)) ("Can you speak more slowly, please?") which is polite and widely used.
