An explicit subject of an infinitive is in the accusative case, while the
subject of a finite verb is in the nominative (ESTE is finite). This
appears to be a feature inherited from Indo-European, and traces of it
are even found in English. Consider:
(1) I want him to go away.
(2) *I want he to go away.
(3) I wish he would go away.
In (1), "him" is the subject of "to go" and is in the objective case. If
the nominative is used, then the sentence would be ungrammatical as (2)
makes clear. Example (3) uses a finite clause, so the subject is in the
nominative case. In these particular examples Greek and English behave
analogously -- that will not always be true.
-- Stephen C. Carlson, George Mason University School of Law, Patent Track, 4LE firstname.lastname@example.org : Poetry speaks of aspirations, and songs http://osf1.gmu.edu/~scarlso1/ : chant the words. -- Shujing 2.35