古爱尔兰语词元的变形形式，依其词性分类。
- Category:古爱尔兰语代词变格形：古爱尔兰语 pronouns that are inflected to display grammatical relations other than the main form.
- Category:古爱尔兰语动词变位形式：词形产生变化（即变位）来表示与原形不同的语法关系的古爱尔兰语动词形式。
- Category:古爱尔兰语名词变格形：古爱尔兰语 nouns that are inflected to display grammatical relations other than the main form.
- Category:古爱尔兰语形容词变格形：古爱尔兰语 adjectives that are inflected to display grammatical relations other than the main form.