In grammar, the infinitive is the form of a verb that has no inflection to indicate person, number, mood or tense. It is called the "infinitive" because the verb is usually not made "finite", or limited by inflection. In some languages, however, there are inflected forms of the infinitive denoting attributes such as tense.

Table of contents
1 English language
2 Germanic languages
3 Romance languages
4 Slavic languages
5 Hebrew language

English language

By far the most common form of an infinitive in English language is with the preposition "to", such as in "to walk", "to cry", "to eat", "to fear". William Shakespeare used a number of infinitives of this form in one of his most famous soliloquies, the "Soliloquy of Hamlet"

  • "To be or not to be..."
  • "To sleep, perchance to dream..."

A less common form of the infinitive is with the conditional auxiliary verbs "may" or "might". An example can again be found in the speech by Hamlet referenced above; "What dreams may come...?". Another example is "we might win".

A third case of infinitive drops the preposition altogether. This is possible when the infinitive form is used in conjunction with a specific set of verbs - these include "feel", "hear", "help", "let", "make", "see", and "watch". Examples include:

  • "I felt the earth move" ("move" is the infinitive)
  • "We heard the bell toll" ("toll" is the infinitive)
  • "She helped me understand ("understand" is the infinitive)
  • "I let him win" ("win" is the infinitive)

The last two cases, where the infinitive appears without to, are called the bare infinitive.

Germanic languages

The original Germanic suffix of the infinitive was -an, with verbs derived from other words ending in -jan or -janan. In German it is -en ("sagen"), with -eln or -ern endings on a few words based on -l or -r roots ("segeln", "ändern"); the use of zu with infinitives is less frequent than to in English. They can function as nouns in the -en form with a capitalized beginning later, in which case they are of neuter gender ("das Essen" means the gerund "eating"). In Scandinavian the n has dropped out and it is -e or -a.

Romance languages

Romance infinitives can be used in much the same way at the "to" form of the infinitive is used in English, and they also can sometimes function as masculine nouns. In Spanish, infinitives always end in -ar, -er or -ir. A similar phenomenon exists in French as well: infinitives of regular verbs have the suffixes -er -ir -oir -re. Italian follows the same pattern, with its infinitives ending in -are, -ere, or -ire.

Formation of the infinitive in Romance languages reflects that of their ancestor, Latin, in which a significant majority of verbs had an infinitive ending with -re (with a varying vowel, called the thematical preceding it).

Slavic languages

The infinitive in Russian ends usually in -t' (ть) preceded by a thematic vowel; some verbs have a stem ending in a consonant and change the t to ch, such as *могть -> мочь "can". Some other Slavic languages have the infinitive typically ending in -ć.

Hebrew language

Hebrew has two infinitives, the infinitive absolute and the infinitive construct. The infinitive construct is used much as an English infinitive, including being preceded by ל "to"; the infinitive absolute is used to add emphasis or certainty to the verb, as in מות ימות "he shall indeed die".

see also split infinitive, infinity, auxiliary verb