adj. 人格高尚的;值得尊敬的;相当数量的
It means that you think someone deserves respect. It generally describes someone else's view of a person.
意思是你认为某人值得尊重。它通常描述别人对另一个人的看法。

例:
Professor Chuang is a respectable scholar.
庄教授是一位值得尊敬的学者。
Respectful /rɪ'spek(t)fʊl/
adj. 有礼貌的;恭敬的
Respectful means 'full of respect', it describes the way in which someone acts, in this case with respect.
Respectful 的意思是“充满敬意的”,它描述了一个人的行为处事是带着敬意的。

例:
It is our duty to be respectful to our parents.
尊重父母是我们的责任。
Respective /rɪ'spektɪv/
adj. 各自的; 各个的
Respective means 'relating to a particular person,thing'.
Respective的意思是“和某些特定的人或物相关的”。

例:
After the game was over the boys returned to their respective houses.
比赛结束后,男孩们回到各自的家。
Respectable通常是形容别人“值得尊敬的”
respectful是说你的态度应该“恭敬的”
respective则是表示“各自的”
今天的内容你都学会了吗?