go skateboarding = skateboard
go surfing = surf
e.g. He goes surfing every night.
He surfs the Internet every night.
go + doing 表示的是“去做..." eg: We'd like to go surfing tomorrow.
surf 也可以做动词用,如,surf the internet(上网) 。但要表示‘去做...’要用“go + V-ing”
如 go skateboarding。
提到go skateboarding ,你可以联想下:go shopping
就是去干嘛,skateboarding是个动名词,两者不能随意互换、下面这个同理
希望可以帮忙