In a purpose construction of the form ‘S in order that S’, subordinate proposition S is called a purpose clause, traditionally a final clause. Proposition S is agentive, that is, its internal structure is ‘A does S’. A purpose construction ‘A does S in order that S’ may be paraphrased by ‘A does S because A wants S’. This shows that the purpose relation is based semantically on the causal relation.

Proposition S is agentive and, thus, controlled. Consequently, E1.a is unproblematic, while E1.b seems to presuppose agency of the budget.

E1.a.The ministery cut down the budget in order that the university should not be burdened by richness.
b.The budget shrank down in order that the university should not be burdened by richness.

Given a relation ‘S causes S’, he who controls S mediately also controls S. A natural constellation is therefore for S and S to have the same agent. Therefore, the same-subject purpose construction is grammaticalized in many languages. A special case of this construction is the motion-cum-purpose construction, where S is a motion of the agent and S is the goal that the agent pursues by this motion. The principal subdivision for purpose constructions is therefore the following:

  1. different subject: E2
  2. same subject: E3
E2.The ministery cut down the budget in order that the university should not be burdened by richness.
E3.The ministery cut down the budget in order to simplify the university's administration.
E4.The minister went shopping.

As illustrated by the examples, structural means for the same-subject constellation are simpler than those for the different-subject-constellation, and those for the motion-cum-purpose constellation are yet simpler.

The purpose clause and the consecutive clause have it in common that both are a causal consequence of the main clause. The difference lies in the semantic component specifying that this consequence is intended by the agent of the main clause. This component is coded in the case of the purpose relation, but not in the case of the consequence relation. It is, however, not excluded from the consequence relation.