With a keyboard open touch and hold the tiny globe icon. After that, choose the left or right keyboard. Then, start typing using your thumb to type comfortably.
Enable the one-handed keyboard from the globe icon
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How to Speed up iOS search
Speed up Spotlight by hiding photo content from search results.
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9 More Hidden iPhone Features and Tricks
Additional iPhone tips including flashlight shortcuts, three-finger gestures, website PDF export, and one-handed keyboard