They gather berries every summer,don't they?
They never gather berries, don they?
They don`t gather berries, do they?
You never see any squirrels in the park, do you ?
You saw some any squirrels in the park, didn't you?
You didn`t see any squirrels in the park, did you?
The train leaves at 10 o`clock, doesn't it?
The train doesn`t leave at 10 o`clock, does it?
The train never leaves at 10 o`clock, does it?
The train left at 10 o`clock, didn't it?