以-ing结尾的adj：表示"让人觉得"。
这个案子让人觉得挫败。
(✔) This project is frustrating.
(✘) This project is frustrated.
这部电影很无聊。
(✔) This film is very boring.
(✘) This film is very bored.
迟到是最烦人的工作习惯。
(✔) Lateness is the most annoying work habit.
(✘) Lateness is the most annoyed work habit.
以-ed结尾的adj：叙述"我觉得"。
我感到很挫败。
(✔) I am very frustrated.
(✘) I am very frustrating.
因此形容一个人时，要先分清你是在形容这个人的个人感情(-ed)，还是这个人给别人的感觉(-ing)，可别再不小心闹笑话了。
John was disappointing. John很扫兴。->让别人很失望。
John was disappointed. John很沮丧。->他自己很失望。