Infinitive (abbreviated INF) is a grammatical term referring to certain verb forms existing in many languages, most often used as non-finite verbs. As with many linguistic concepts, there is not a single definition applicable to all languages. The word is derived from Late Latin [modus] infinitivus, a derivative of infinitus meaning "unlimited".
In traditional descriptions of English, the infinitive is the basic dictionary form of a verb when used non-finitely, with or without the particle to. Thus to go is an infinitive, as is go in a sentence like "I must go there" (but not in "I go there", where it is a finite verb). The form without to is called the bare infinitive, and the form with to is called the full infinitive or to-infinitive.
In many other languages the infinitive is a single word, often with a characteristic inflective ending, like morir ("(to) die") in Spanish, manger ("(to) eat") in French, portare ("(to) carry") in Latin, lieben ("(to) love") in German, etc. However some languages have no forms which can be considered to be infinitives. Many Native American languages and some languages in Africa and Australia do not have direct equivalents to infinitives or verbal nouns; in their place they use finite verb forms in ordinary clauses or various special constructions.