Is this sentence from the Italian Athenaze II, page 251, ambiguous?
Οἱ νεανίαι νομίζουσι τοὺς πολεμίους ῥᾳδίως νικήσειν.
Can it men, both: “The youth consider that it will be easy to conquer the enemy.” and “The youth consider that the enemy will easily conquer.”
Yes, it’s ambiguous.
(1) The young men think they will easily defeat the enemy. Not “it will be easy to defeat the enemy”; the subject of the active infinitive νικήσειν in this interpretation is οἱ νεανίαι is the subject of both νομίζουσι and νικήσειν and it remains notionally nominative in indirect speech, rather than accusative,even though it’s the subject of the infinitive. νικήσειν in this interpretation is transitive.
(2) The young men think the enemy will easily win. In this interpretation νικήσειν is intransitive. νικαω can be either transitive or intransitive in Greek. τοὺς πολεμίους is the accusative subject of νικήσειν.