Morphological rules are exceptions to the orthographic rules

Orthographic rules

Orthographic rules are general rules used when breaking a word into its stem and modifiers. An example would be: singular English words ending with -y, when pluralized, end with -ies. Contrast this to Morphological rules which contain corner cases to these general rules. Both of these types of...

 used when breaking a word into its stem and modifiers. An example would be while one normally pluralizes a word in English by adding 's' as a suffix, the word 'fish' does not change when pluralized. Contrast this to orthographic rules

Orthographic rules

Orthographic rules are general rules used when breaking a word into its stem and modifiers. An example would be: singular English words ending with -y, when pluralized, end with -ies. Contrast this to Morphological rules which contain corner cases to these general rules. Both of these types of...

 which contain general rules. Both of these types of rules are used to construct systems that can do morphological parsing

Morphological parsing

Morphological parsing, in natural language processing, is the process of determining the morphemes from which a given word is constructed. It must be able to distinguish between orthographic rules and morphological rules...

.