Amazon.com Inc. is promising to entertain children with a device that spits out knock-knock jokes on demand and will also teach them good manners.

The company will release new kid-focused skills for its Alexa digital assistant on May 9, along with an $80 Echo Dot voice-controlled speaker designed for children.

The gadget comes with "FreeTime on Alexa," which lets parents turn off voice purchasing, filter songs with bad words that their children might stream and set time limits to stop kids chatting to Alexa late into the night.

Children can say, "Alexa, I'm bored," to get an age-appropriate suggestion, or ask for a song or knock-knock joke. A new "Magic Word" feature encourages kids to say 'please' when asking Alexa questions. Those paying $3 a month get more, like Audible children's books and kid-friendly music stations.

The Echo Dot Kids Edition includes a two-year guarantee.

Echo speakers can be used to set alarms, thermostats and dim lights via voice command, as well as shop. The company is also creating new subscriptions to boost revenue. More than 100 million Prime members already pay yearly or monthly fees in exchange for fast shipping, video and music streaming.