楼上只对了一半,
was able to 是否等于 managed to do?
虽然 was able to 的字面意思是“能够做”,一般会讲英语的人会理解为
不仅能够做,也做好了.
因此,从习惯语的观点来说,如果你对人说
I was able to do it
和
I managed to do it
听者会理解为意思相同.
希望帮到了你.