fun作名詞時，不可數。
1N-UNCOUNT 趣知事;樂趣 You refer to an activity or situation as fun if you think it is pleasant and enjoyable and it causes you to feel happy.
This year promises to be terrifically good fun.
今年一定會非常有意思。
2N-UNCOUNT 有趣道的人;好玩的人 If you say that someone is fun, you mean that you enjoy being with them because they say and do interesting or amusing things.
Liz was wonderful fun to be with.
莉茲是個非常有趣的夥伴。
fun作名詞時，不可數。
1N-UNCOUNT 趣知事;樂趣 You refer to an activity or situation as fun if you think it is pleasant and enjoyable and it causes you to feel happy.
This year promises to be terrifically good fun.
今年一定會非常有意思。
2N-UNCOUNT 有趣道的人;好玩的人 If you say that someone is fun, you mean that you enjoy being with them because they say and do interesting or amusing things.
Liz was wonderful fun to be with.
莉茲是個非常有趣的夥伴。