Major Uses of the Nominative Case
The nominative case is the simplest Greek case, yet it is used for more than merely marking the subject of a sentence.
The student of the New Testament will find the following uses:
1. Subject Nominative
By far the most common use. Nouns in the nominative case usually serve as the subject of a sentence.
The light shines in darkness (1 John 1:5).
2. Predicate Nominative
Whenever a sentence uses a form of the verb "to be" (Greek eimi or ginomai), the nominative case is used both before and after the verb - as the subject and as the predicate.
God is love (1 John 4:8)
3. Nominative of Apposition
A nominative noun may simply be sitting beside another nominative noun, serving as a further description for that noun. The first noun might serve as the subject of the sentence, but the second noun is another name for the same person or thing.
Philip the evangelist (Acts 21:8)
4. Nominative of proper names
Some proper names always occur in the nominative case, regardless of how they are used in the sentence. This is particularly common when the name is borrowed from another language like Hebrew.
. . . saying to Aaron (Acts 7:40)
5. Nominative for direct address
Most nouns do not have a separate ending for the vocative case, which is used for direct address: speaking to someone and calling them by name. Nouns that do not have a vocative form use the nominative case for direct address.
Hail, king of the Jews! (John 19:3)
6. Nominative in Exclamations or Fragments
The nominative is used for exclamations or other phrases that are not integrated with the regular structure of a sentence.
O the depth of the riches and wisdom and knowledge of God! (Romans 11:33)