这里为什么要加ing?Are they good at helping you?

这里为什么要加ing?Are they good at helping you? you are very good at telling stories.为什么要加ing ?” that's what you are good at这里为什么要加what?类似的还有you are what you they are waiting for you为什么加ing Are you good at dangcing?这里的为什么要用Are? Tank you for helping me.中的help为什么加ing? thank you for helping me 中help为什么要加ing They are watching TV watch为什么要加ing Thanks fou helping me help为什么要加ing You are eating too much!这里的eat为什么加ing they are hanging out in the shop.they are free.为什么hang要加ing You are very good at telling strories 翻译意思,为什么要用at tell为什么要加