the old man lives in a village alone , but he doesn't feel lonely.

本句中alone 指无人作伴,孤独一人 lonely指自己感到孤独寂寞.
alone为形容词,意为“单独的”,只作表语,不能作定语.侧重说明独自一人,没有助手或同伴
lonely意为“孤独的”,表示主观上感到孤独、寂寞,指因缺少朋友、同情、友谊等产生的一种悲伤和忧郁的感情.
She went home alone.
她独自回家去了.
After his wife died,he lived alone.
他的妻子死后,他一个人生活.