形容詞 painful:

1. causing physical or psychological pain
2. causing misery or pain or distress
   同義詞：afflictive, sore
3. exceptionally bad or displeasing
   同義詞：atrocious, abominable, awful, dreadful, terrible, unspeakable
4. causing physical discomfort
   同義詞：irritating

1. Teaching him Greek was a painful (ie slow and difficult) process.
   教他希臘文是很吃力的事。
2. The sting of a jellyfish is very painful.
   讓水母刺著是很痛的。
3. Extension of the injured arm was painful.
   把受傷的胳膊伸展開是很疼的。
4. He gained the medal through his painful travail.
   他通過艱辛的努力獲得了獎牌。
5. An extremely unpleasant or painful condition or place.
   逆境極其不舒服或痛苦的境地或地方
6. The child's death left a painful void in his parents' lives.
   孩子的死給父母的生活留下了痛苦的空白。
7. The operation was very painful.
   手術(shù)很痛。
8. It was painful to admit that I was wrong.
   要我承認錯了，是很費力的。

pain.ful

adj.（形容詞）
Causing pain.
引起疼痛的
Full of pain.
充滿痛苦的
Requiring care and labor; irksome:
需要費心費力的；使人討厭的：
例句：
a painful task.
費力的工作

Archaic Diligent; careful.
【古語】 孜孜不倦的；勤勉的

【引伸】
pain.fully
adv.（副詞）
pain.fulness
n.（名詞）