er at leve "to travel is to live", jeg elsker at spise kartofler "I love to eat potatoes". Furthermore, the Danish infinitive may also be governed by a preposition (where English normally has the gerund): han tog livet af sig ved at springe ud af et vindue "he killed himself by jumping out of a window". The infinitive normally has the marker at, pronounced or in normal speech , thereby being homonymous with the conjunction og "and", with which it is sometimes confused in spelling. The bare infinitive is used after the modal verbs kunne, ville, skulle, måtte, turde, burde. A rarer form is the verbal noun with the ending -en (not to be confused with the definite article) which is used when the infinitive carries a pronoun, an indefinite article or an adjective: hans evindelige skrigen var enerverende, "his never-ending crying was enervating", der var en løben og råben på gangene, "people ran and cried in the hall". This use has a connotation of something habitual and is often used in a negative sense. It is used in formal information like Henstillen af cykler forbudt, "It is prohibited to leave your bike here." Whereas the infinitive is accompanied with adjectives in the neuter (det er svært at flyve, "it is difficult to fly"), the verbal noun governs the common gender. Due to the rarity of this form, Danes often mistakenly write Henstilling af cykler forbudt (lit. "Recommendation of bikes prohibited") instead, using a more familiar word form. Verbal nouns like viden "knowledge" (literally: "knowing") or kunnen "ability" (literally: "being able") have become lexicalised due to the influence of German (Wissen, Können). Like the proper verbal noun, these forms have no plural, and they cannot carry the definite article; so, when English has the knowledge, Danish must use a pronoun or a circumlocution: e.g. hans viden, denne viden, den viden man havde. Danish has various suffixes for turning a verb into a real noun: the suffix -(n)ing: hængning "hanging" (: hænge), samling "collection" (: samle). The suffix, which is still productive, is related to the German -(n)ung and the English -ing. Words with this suffix belong to the common (originally feminine) gender. The variant without -n- is used after stems ending in n, nd, r and consonant + l. the suffix -else: bekræftelse "confirmation" (: bekræfte). The suffix, which is still productive, takes the common gender. the suffix -sel: fængsel