There are three ways to add words or sentences to your list of Favorites.
• The first method is to:
1. Go to the "You" tab.
2. Tap on "Favorites". 
3. Tap on the group to which you want to add words or sentences.
4. Tap the "Add" button. 
5. Select words or sentences from the list. You can also use the Search or Filter.
6. Tap the "Add" button.
• The second method is to tap the Favorites icon (star) straight from the Vocabulary.
• The third method is to tap the Favorites icon (star) from the Search features.
Note: The words or sentences added by the second or third method will be be automatically added to the default "My Favorites" group.
At this point in time, the Favorites feature is available only upon Paid Subscription and only on Android devices.
How do I subscribe?
How do I add a group of Favorites?