Zero-valency ones exist in Mandarin Chinese but not English.
These things can have the property of telicity, without which they are atelic.  In government and binding theory, each of these entities has a "theta-grid" from which it assigns theta-roles. In the X-Bar model, one of these lexical items is preceded by an IP head. Zero-valency ones exist in Mandarin Chinese but not English. In French, their syntax can involve a namesake "raising," and each one in Ancient Greek has two aorist forms. The "modal" and "auxiliary" subtypes of these words alter other words of this kind, which can be in different moods or voices. For 10 points, name this class of words whose intransitive examples have no direct object, which are altered by conjugation, and describe states or actions.
These things can have the property of telicity, without which they are atelic.  
verbs [accept verb phrases until "theta-grid" is read, but not thereafter]