Sure, you can send text messages on an iPhone or iPad using the virtual keyboard. However, it’s easier to do it using Siri, Apple’s “personal digital assistant.” Here’s how to do this:
Press and hold the Home button to activate Siri (or say “Hey, Siri” if you iPhone supports this feature).
Say something like “Text Laura Sellers” or “Send text to Laura Sellers.” Siri opens your Messages app and puts the name of the person you’re texting in the To field.
Siri will ask, “What do you want your message to say?” Dictate your text message.
When you’re done, Siri shows you the message and asks you if you want to send it.
Say “Yes” or “Send” to send the message. Or say “No” or “Cancel” to cancel the message.
(This how-to is based on my experiences and info on Apple’s support pages — where the images sometimes come from.)