It's great fun playing with him. play为什么要用ing形式

it's great fun是啥意思? It's great fun ____(visit)Disneyland. great fun 中fun的词性是什么It's Great fun +doing还是to do?这里的fun 为什么词性? It's great fun _______(chat) with each other. I think it's great fun to () them. 英语改错 “It's a great fun working with him” It's great fun to play with them.是什么句型?fun是什么词性?能多举几例吗? It was great fun!还是：it sounds great fun? it+was+great+fun是什么意思 It was great fun.感叹句 it must be great fun.great It's------to swim in the river in summer.A.a great fun B.a great funny C.great fun D.great funn It's great fun ( )with it.A.playing B.played c.play D.plays讲清理由 John thinks it’s _____ to talk with you.A.very fun B.great fun应该填哪个? It's great fun to play chess in the park.（改为感叹句） It's great ______ to play with my pet(fun funny) It's great fun ___(jump)into the river and ___(swim)in summer. It's great fun ____ with him.A.playing B.played C.play D.plays