Type to Siri is a new feature in iOS 11 allows you to type your questions or requests to Siri rather than requiring you to speak. This is very convenient for users who have difficulties speaking to Siri.
When you invoke Siri, you’ll find a new text field right above the keyboard where you can type in your question to be answered by Siri. By default, Type to Siri is disabled in iOS 11 so you have to enable it manually.
Here’s how to enable Siri and Type to Siri in iOS 11.
Step 1: Open Settings and tap on General → Accessibility
Step 2: Swipe down and tap on Siri
Step 3: Tap the toggle for Type to Siri
Once you’ve enabled this feature, press and hold the Home button to invoke Siri. Right above the keyboard, you’ll notice that there’s a new text field. Type your query within this text field, then press the Done button in the bottom right corner of the keyboard.