How to connect your Google account to Cortana
1. Open Cortana .
2. Click the Notebook button.
3. Select Connected Services.
4. Click the Add a service button.
5. Select Gmail from the list.
6. Click the Connect button.
7. Sign in using your login credentials.
8. Click the Allow button to allow Cortana to access your account.
Once you’ve completed the steps, you can use Cortana to interact with your Google Calendar. Giving Cortana access to your Google account will allow access to your Google Contacts, Google Drive, Gmail, and other information.
If you want to disconnect your account, go to https://myaccount.google.com/permissions and revoke access for Outlook.
It should be noted that this feature is new, and it may take a while to see it working. Also, at this time, this feature is not available for iOS or Android.