Marking of the temporal structure of an event.

Aspect is the marking of the temporal structure of an event. Some commonly marked aspects are:

  • perfective aspect: this treats an event as a single unitary event without any internal temporal structure, eg 'I ate dinner'. The event is seen as a whole.
  • imperfective aspect: this treats an event as having internal structure as an ongoing event, eg 'I was eating dinner'. The event is seen as a sequence of activities.
  • perfect aspect: this refers to the event as having been recently completed, eg 'I have eaten dinner'.

Aspect is distinct from tense, which marks the location in time of an event (and may be relative or absolute), and from mood, which marks the speaker's attitude towards the event. These three categories are often found as properties of the verb and are commonly referred as TAM.