Preverb

A preverb is a word or morpheme that typically precedes a verb and modifies its meaning, often indicating direction, completion, or aspect. It functions somewhat like a prefix, but is often considered a separate word or a clitic rather than a bound morpheme strictly attached to the verb.

Preverbs are common in certain language families, such as the Slavic, Celtic, and Algonquian languages. Their function and grammatical status can vary considerably from language to language. Sometimes, a preverb may be separable from the verb, while in other instances it may be written directly adjacent to it.

The effect of a preverb can range from subtly altering the nuance of a verb to radically changing its meaning, creating a new verb with a distinct sense. For example, a preverb might indicate whether an action is inward or outward, completed or ongoing, successful or unsuccessful. The meaning of a verb combined with a particular preverb is not always predictable from the independent meanings of the verb and the preverb. Over time, certain verb+preverb combinations may develop idiomatic meanings.

The distinction between a preverb and a prefix can be subtle and is often debated by linguists, hinging on criteria such as separability, stress patterns, and historical development.