We all had a grand day out at the Fun Fair.
Chasing my sister around the garden with a water pistol is such fun.
The activities were fun
"much fun"
He said that he is going to have fun tonight.
"I love my boyfriend because he is so outgoing and fun."
Life is full of uncertainties. We have no plans, the uncertainties are part of the fun.
Dog agility is a fun sport to watch.
Fun is an adjective in this sentence because it does not tell how was which was or where was.
When it is pollen which is spring it is very fun on that day. My mom told me to pollinate the plants!
It's no fun trying to dodge mid-day traffic in the downtown area.
The people rejoiced in much merriment. "Merriment" means gaiety and fun.
The adjective in the sentence 'you finally left and had a fun day' is left & fun.
fun