Have fun!
They're having lots of fun in the pool.
She's fun to be with.
I really enjoyed your party - it was a lot of fun.
It's no fun/not much fun having to work weekends.
I hope we have a great meal and a lot of fun. (Skills for Life (Entry 1); A1; Polish)
I ran but just for fun.
Fortunately I discovered that [the e-mail] wasn't for me. I didn't appreciate that there were people that were sending things like that just for fun. (Preliminary English Test; B1; Italian)
The other children at school used to make fun of his hair.
I didn't want to tell other people because I didn't want them to make fun of me. (First Certificate in English; B2; Spanish)
There are lots of fun things to do here.
I can remember my birthday party and all the fun things we did. (Key English Test; A2; Somali)