Experience (both from work on either Alexa or a similar system in previous years, and as an actual user) tells me that yes, people do often say things that don'

Experience (both from work on either Alexa or a similar system in previous years, and as an actual user) tells me that yes, people do often say things that don't "look correct". From personal experience I know that something about the pressure of knowing that the device will detect the end of your utterance before you're ready, if you're silent for too long, can end up rushing you and scrambling your brain a little. Even if you ordinarily have near-perfect instincts for English grammar and sentence construction, you can end up saying some pretty weird things. But thinking of them as user mistakes, and framing them as "correct" or "incorrect", is counterproductive here. It may be a useful distinction as a learner, when you're trying to improve your own command of the language. But when they're inputs to your system, you have to do your best to do what the user meant, if that's possible to infer. All three of your examples are actually clear, if nonstandard (play music again; tell me what album the currently playing music is from; list my alarms). So a system that takes these as input should handle them as valid requests, not classify them as "incorrect". It might be different for a system designed to teach 'proper' English, rather than a system designed to enact the user's will.