This month, my Scientific American column described Viv, a next-generation voice assistant that's been created by the team who originally brought us Siri (or, rather, brought Siri to Apple).

Now, I meet people all the time who say, "Oh, I never use Siri" (or Google Now or Microsoft’s Cortana). "It's just not accurate enough."

Ah, but there's a big difference between dictating text to your phone, which sometimes produces errors—and issuing commands, which almost never makes a mistake. And in many cases, speaking your command is much faster than performing it manually, by tapping your way through things on the screen.

Here, for example, are 10 Siri commands on the iPhone or iPad that you should start using right now, if you're not already. You'll find that they work crisply, without errors, and they save you a lot of time.

1. "Open Calendar."
If you don't learn to use Siri for anything else, learn this one. You can say, "Open Uber" or "Play Angry Birds" or "Launch Weather"—the corresponding app opens instantly. You don't have to return to the Home screen and hunt for the proper app.

2. "Set my alarm for 6:30 A.M."
It's so much faster to say this than to fiddle with the little on-screen dials to set an alarm in the Clock app.

3. "Call Nicole on her cell phone."
Siri places the call. At this point, it's just as though you'd initiated the call yourself. Similarly: "Call the office." "Phone home." "Dial 867-5309." "Start a FaceTime call with Mom." "FaceTime George."

4. "Read my new messages."
Of course, if you're driving, you shouldn't be using your phone at all. But if you hear a text message come in, and you must hear it now, at least this command lets you hear the text message read aloud without looking at the phone.

5. "Tell Susan I'm running late."
The verb "tell" means "Send a text message." So this command will send Susan a text message like this: "I'm running late." (Similarly: "Send a text to Bill Jenkins." "Send a message to Casey saying, 'You left your socks here.'" "Send a message to Ellen’s mobile asking her to pick me up at the train." "Send a text message to 262-556-2282." "Text James and Sarah: Did you remember the water skis?") In each case, Siri shows the message, all typed up, and asks if you want to send it; say "Yes," "Send," or "Confirm" to proceed.

6. "Make the screen brighter."
Not only does Siri brighten your screen a notch, but she also displays the Brightness slider in case you want to adjust it further.

7. "Turn on Bluetooth" or "Turn off wi-fi."
You can even say, "Turn on Airplane mode." (You can't turn off Airplane mode by voice, though because Siri doesn't work without an Internet connection.)

8. "Remind me to feed the dog when I get home."
A Reminders entry form appears, showing the alarm that Siri has created; it will pop up when get home. (The phone relies on GPS to know when you're home. It understands "home" and "office," both yours and other people's—if you've entered those addresses onto the corresponding people's cards in Contacts.) Similarly: "Remind me to bring the science supplies to school." "Remind me to take my antibiotic tomorrow at 7 A.M." "Remind me to call Dad when I leave here.”

9. "Make an appointment with Jon for Thursday at 3 P.M."
Yes, Siri can note appointments for you, which is much faster than tapping them into the Calendar app with your fingers. "Set up a massage at 11." "Set up a meeting with Frank this Monday at noon." "Meet Kim Coppersmith at 6." "New appointment with Tracy, next Tuesday at 8.” “Schedule drinks with Mike tonight at 9.”

You can also move meetings by voice. For example, "Move my 3:00 meeting to 4:30." "Reschedule my meeting with Frank to a week from Monday at noon." "Cancel the conference call on Tuesday."

Siri can even check your calendar. You can say, "What's on my calendar today?" "What's on my calendar for October 10?" "When's my next appointment?" "Where is my next meeting?" "When is my meeting with Frank?"

10. "What song is this?" or "Name that tune!"
Siri listens to whatever music is playing at the moment—and identifies the song’s name and performer. There is also, of course, a Buy button. (That's something the iPhone can't do in any other way besides using Siri.)