[iMore.com]

If you're left handed, don't worry — Apple's made it easy to set up your Apple Watch for left-handed use!
During setup, the Apple Watch will ask you which wrist you intend to wear it on. Answer, an it will automatically set it up for the proper wrist. If you later change your mind, however, or lend it to someone who wants to wear it on a different wrist, it's easy to change.

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