When you have two or more entries for the same contact, you can merge them into a single entry. You can also separate contacts that were merged.
Open the Contacts app, then tap the contact entry you want to join with another entry.
Tap the Menu icon .
Tap Manage contacts, and tap Merge.
Tap a suggested entry or tap Show all contacts to select another entry.
Once entries have been merged, Separate is included in the Options menu to allow you to separate the joined entries.
Open the Contacts app, then tap the contact entry you want to separate.
Tap the Menu icon .
Tap Separate.
Tap YES.