The original Proto-Germanic ending 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", "andern"). The use of zu with infinitives is similar to English to, but is less frequent than in English. German infinitives can function as nouns, often expressing abstractions of the action, in which case they are of neuter gender: das Essen means the eating, but also the food. In Dutch infinitives also end in -en (zeggen — to say), sometimes used with te similar to English to, e.g. "Het is niet moeilijk te begrijpen" > "It is not difficult to understand." The few verbs with stems ending in -a have infinitives in -n (gaan — to go, slaan — to hit). Afrikaans has lost the distinction between the infinitive and present forms of verbs, with the exception of the verbs "wees" (to be), which admits the present form "is", and the verb "he" (to have), whose present form is "het". In North Germanic languages the final -n was lost from the infinitive as early as 500–540 AD, reducing the suffix to -a. Later it has been further reduced to -e in Danish and some Norwegian dialects (including the written majority language bokmal). In the majority of Eastern Norwegian dialects and a few bordering Western Swedish dialects the reduction to -e was only partial, leaving some infinitives in -a and others in -e (a laga vs. a kaste). In northern parts of Norway the infinitive suffix is completely lost (a lag’ vs. a kast’) or only the -a is kept (a laga vs. a kast’). The infinitives of these languages are inflected for passive voice through the addition of -s or -st to the active form. This suffix appeared in Old Norse as a contraction of mik (“me”, forming -mk) or sik (reflexive pronoun, forming -sk) and was originally expressing reflexive actions: (hann) kallar (“(he) calls”) + -sik (“himself”) > (hann) kallask (“(he) calls himself”). The suffixes -mk and -sk later merged to -s, which evolved to -st in the western dialects. The loss or reduction of -a in active voice in Norwegian did not occur in the passive forms (-ast, -as), except for some dialects that have -es. The other North Germanic languages have the same vowel in both forms. [edit]Latin and Romance languages The formation of the infinitive in the Romance languages reflects that in their ancestor, Latin, almost all verbs had an infinitive ending with -re (preceded by one of various thematic vowels). For example, in Italian infinitives end in -are, -ere, -rre (rare), or -ire, and in -arsi, -ersi, -rsi, -irsi for the reflexive forms. In Spanish and Portuguese, infinitives end in -ar, -er, or -ir, while similarly in French they typically end in -re, -er, oir, and -ir. In Romanian the so-called "long infinitives" end in -are, -ere, -ire and they are converted into verbal nouns by articulation (verbs that cannot be converted into the nominal long infinitive are very rare[4]). The "short infinitives" used in verbal contexts (e.g. after an auxiliary verb) have the endings -a,-ea, -e, and -i (basically removing the ending in "-re"). In Romanian, the infinitive is usually replaced by a clause containing the preposition sa plus the subjunctive mood. The only verb that is modal in common modern Romanian is the verb a putea, to be able to. But in popular speech, the infinitive after a putea is also increasingly replaced by the subjunctive. In all Romance languages, infinitives can also be used as nouns. Latin infinitives challenged several of the generalizations about infinitives. They did inflect for voice (amare, "to love", amari, to be loved) and for aspect (amare, "to love", amavisse, "to have loved"), and allowed for an overt expression of the subject (video Socratem currere, "I see Socrates running"). Romance languages inherited from Latin the possibility of an overt expression of the subject (as in Italian vedo Socrate correre). Moreover, the "inflected infinitive" (or "personal infinitive") found in Portuguese, Galician, and (some varieties of) Sardinian inflects for person and number. These are the only Indo-European languages that allow infinitives to take person and number endings. This helps to make infinitive clauses very common in these languages; for example, the English finite clause in order that you/she/we have... would be translated to Portuguese as para teres/ela ter/termos... (Portuguese is a null-subject language). The Portuguese personal infinitive has no proper tenses, only aspects (imperfect and perfect), but tenses can be expressed using periphrastic structures. For instance, even though you sing/have sung/are going to sing could be translated to apesar de cantares/teres cantado/ires cantar. Other Romance languages (including Spanish, Romanian, Catalan, and some Italian dialects) allow uninflected infinitives to combine with overt nominative subjects. For example, Spanish al abrir yo los ojos ("when I opened my eyes") or sin yo saberlo ("without my knowing about it").
