This may  not seem like a big deal, but it is. Whispering uses many different types of vocal manipulations. This is something that Google Home cannot yet do. Just ask Alexa, "Alexa, do you know how to whisper?" and she will respond something cute like, " Yes. I can whisper. I learned after I realized that people take naptime very seriously."  Actually whispering somes in handy when someone in the room is sleeping.