The man took heart and, sure enough, on New Years' Eve he was able to hobble along to a party. 系动词是was吗

问题描述:

The man took heart and, sure enough, on New Years' Eve he was able to hobble along to a party. 系动词是was吗
不定式是状吗to a party 是定吗

be able to 是固定用法,某种意义上相当于can
to a party 是地点状语...