Extent: Spatial Or Temporal [Diagnostic: Interrogative Probe]

Halliday & Matthiessen (2014: 315):

Extent construes the extent of the unfolding of the process in space-time: the distance in space over which the process unfolds or the duration in time during which the process unfolds.  The interrogative forms for Extent are how far?, how long?, how many [measure units]?, how many times?.