Legatos misit ad pacem petendam. "He sent messengers to ask for peace."
Legatos misit pacis petendae causa. "He sent messengers to ask for peace."
Urbi condendae locum elegerunt. [Livy V. 54.4] "The chose out a site for founding a city."
Pecuniam dedit mihi servandam. "He gave the money to me to be kept." [N.B.: dative of agent after passive]
Miles gladium strinxit in mortem eius. "The soldier drew his sword with a view toward his death."
VII. THE SUPINE in the ACCUSATIVE (of the GOAL):
The supine (like the infinitive) is an abstract verbal noun. It is of the Fourth Declension Masculine (cf. the Gerund, which is also masculine), but only the accusative and ablative singular forms are in use. The functions which its other (now non-existent) forms might have had are performed by the infinitive and the gerund. The supine resembles the infinitive and the gerund in that the accusative supine of a transitive verb governs an accusative object, and is not qualified by an objective genitive.
FORMS OF THE SUPINE:
Notice that the accusative supine looks exactly like the accusative singular (m/n) of the fourth principle part of a verb (the perfect passive participle, a verbal adjective).
THE ACCUSATIVE OF THE SUPINE is used as an Accusative of the goal-of-motion, to express the idea of purpose (without the preposition):
Legatos ad Caesarem mittunt rogatum auxilium. "They are sending messengers to Caesar to ask for assistance."
John Paul Adams, CSUN