set out:
出发,开始,侧重于开始做某事,还有规划,展现的意思
例句与用法:
They succeeded in what they set out to do.
他们打算做的事已经做成了.
set about:
开始,着手,与set out意思相近,但set out后加不定式,即set out to do sth,而set about后加 ing形式,即set about doing sth.
例句与用法:
1. You must set about your work at once.
你必须立即开始工作.
2. Do you know how to set about going on this work?
你知道怎样着手进行这项工作吗?