A standard fully declinable singular: زَيْدٌ، زَيْدًا، زَيْدٍ. The three case forms take the usual endings; an indefinite noun can bear tanwīn.
A normal diptote example: أَحْمَدُ، أَحْمَدَ، أَحْمَدَ. It lacks tanwīn and, without al- or iḍāfah, has fatḥah in the genitive.
Now see what happens when the proper-name function is removed.
| Word | Meaning |
|---|---|
| زَيْدٌ / زَيْدًا / زَيْدٍ | Nominative, accusative, genitive of a triptote |
| أَحْمَدُ / أَحْمَدَ / أَحْمَدَ | Normal case endings of a diptote proper name |