A few easy ways to  show more/less enthusiasm in your opinions

, in English:

With the example question "how was the party yesterday?" 

Instead of just saying "It was fun", you can use an adverb before the adjective, to make your reply more specific. These are all very very common:

"It was really fun/it was so fun/it was seriously fun"  -   is like using "very", to express stronger enjoyment

"It was quite fun/it was pretty fun"   -   less enthusiastic. You liked the party but you didn't think it was amazing. "Pretty" is usually more positive than "quite"

"It was mostly fun"   -   this suggests that the party was good, but there was some specific  part of it that you didn't enjoy

"It was kind-of fun/it was sort-of fun"   -   this is very vague, and suggests your feelings about the party are mixed, or confused, and that you are not enthusiastic about it

"It was weirdly fun"   -   this suggests either that you were surprised that you enjoyed it, or that it was a strange but good experience for some reason