| Singular Nominative | cathaoir |
| Singular Genitive | cathaoireach |
| Plural Nominative | cathaoireacha |
| Plural Genitive | cathaoireacha |
| Singular Nominative | an chathaoir |
| Singular Genitive | na cathaoireach |
| Plural Nominative | na cathaoireacha |
| Plural Genitive | na gcathaoireacha |