"HAVE FUN DOING STH" 和" HAVE IN DOING STH " 有什么区别?,可以通用吗?

have fun (in) doing sth．开开心心做某事

have fun意为“过得快活”，后常接动词－ing形式，其前的介词in可以省略.相当于enjoy oneself，have a good time。如：

The boys are going to have fun (in) drawing the pictures.

have fun doing sth.跟have fun in doing sth.没什么区别,可以通用.

更多的类似例子:

have problems（in）doing sth．做某事有困难

problem后接动词－ing形式，其前的介词in可以省略。如：

They had no problem（in）fixing the car．

have fun doing sth 表示做某件事很有乐趣，有兴趣。
后者只是表示正在做某件事，不含感情色彩。

yes