I happened on one occasion to be spending a few days there,waiting for a ship, and I was introduced to him at the British Club.
有一次我碰巧在那里呆几天,等一艘船,我在英国俱乐部认识了他。
这里非谓语动词结构waiting for a ship是伴随状语或者理解为目的状语也可以。
学好从句之前学好句子的成分很重要。