Article in English: Siri is enabled by default on all devices that support it, so usually you can just press and hold the Home button to start the Siri interface. The Siri prompt will appear, and you'll be able to speak your command or question. If Siri doesn't start, it may be disabled or your iOS device may be too old. See the next section for details. When your iOs device is plugged in, you can say "Hey Siri" to launch the Siri interface without pushing any buttons.  The iPhone 6s, iPhone 6s Plus, iPhone SE, and iPad Pro allow you to use "Hey Siri" without the device being plugged in. If "Hey Siri" isn't working, it may need to be turned on. See the next section for details. If you have a Bluetooth headset, press and hold the Call button until you hear a short notification chime. You can then speak your command or question. If you're using CarPlay in your car, you can start Siri by pressing and holding the Voice button on your steering wheel. You can also press and hold the digital Home button on your CarPlay display. If you use an Apple Watch, you can start Siri by bringing the watch up to your face. As soon as you raise your watch, you can start speaking the command or question.

Summary in Vietnamese:
Nhấn và giữ nút Home. Nói "Hey Siri" (Xin chào Siri) nếu thiết bị iOS đang được kết nối với nguồn điện. Nhấn và giữ nút gọi trên tai nghe Bluetooth. Nhấn và giữ nút Voice trên vô-lăng để khởi động Siri với CarPlay. Đưa đồng hồ Apple Watch lên mặt để khởi động Siri.