If you are getting Duolingo emails, but have not intended to create an account on Duolingo, someone else might have entered your email address when they made their account. Luckily you have full control over the account now and have the right to disable it by verifying that you are the email holder. Simply follow these steps to deactivate the fraudulent account:
1. Visit duolingo.com.
2. Under "Login", select "forgot password" and follow the steps to send yourself a reset email.
3. Check your email and follow the link to reset your password.
4. Choose a new password and continue to Duolingo, signed in to the account.
5. Visit "Settings" and under "Account", change the email address to any other and "Save Changes". If you instead wish to remove the other person's account altogether, select "Disable my account". Confirm.
When creating a Duolingo account, it is imperative to use your own email, not a made up one or someone else's. Creating an account under an email address that is not your own will make it impossible for you to recover a lost password and receive notifications, and also allow someone else to take control of the account and delete it. An account made with an email address other than your own risks deletion at any time, without previous notice.