A morphologizer, often called a conjugator, is an online tool that allows users to understand and apply the morphological rules of a language. A morphologizer also often includes information on parts of speech (relevant for the application or non-application of morphology rules) as well as additional terminological information, such as base or citation forms and classes or senses, when relevant.

Essentially, it splits each word into its constituent parts when parsing, and builts inflected or derived strings from lexical roots (also called stems) or base forms for natural language generation.

Morphology analyzes the structure of words and parts of words such as stems and roots, prefixes, suffixes and infixes, as well as phonological phenomena that play an important part in morphological operations.

A morphologizer should include both inflectional and derivational morphology. It is through morphology that speakers build and understand inflected (book/books) and derived (sing/singer) strings.

A morphologizer, as a tool, should also include links to descriptions of the language at hand. This, in turn, facilitates the creation of additional linguistic resources.

Morphologizers are excellent tools for native and non-native speakers to improve their linguistic abilities.