Single-domain thesis for verbs: The meaning of a verb (verb root) is
a convex region of vectors that depends only on a single domain.
For example, push refers to the force vector of an event (and thus
the force domain), move refers to changes in the spatial domain of the
result vector and heat refers to changes in the temperature domain.12
The single-domain thesis for verbs is analogous to the single domain
thesis for adjectives. The thesis entails that there are no verbs that
mean ‘walk and burn’ (multiple domains) and there are no verbs that
mean ‘crawl or run’ (not convex).
Since the model requires that an event always contains two vectors,
the constraint entails that a single verb cannot completely describe an
event, but only bring out an aspect of it. However, the two-vector model
has the testable consequence that a construal can always be expanded
to contain references to both the force and result vectors. More precisely,
for any utterance based on a construal involving only a force vector,
one can always meaningfully ask “What happened?”; and for any utterance
based on a construal involving only a result vector one can always
ask “How did it come about?”
According to the model, verbs have two main roles: (1) To describe
what has happened (or will happen); and (2) to describe how it happened
(or will happen). This is refl ected linguistically by the distinction
between result verbs, for example, run, hit, and wipe, and manner
verbs, for example, fall, boil, and clean (Rappaport Hovav and Levin
2010; Warglien et. al 2012). A special case is when nothing happens,
that is, when the event is a state. Verbs describing states such as stay,
live and the most general is are all result verbs.