need的否定形式是don't need。don't need的例句：You don't need green fingers to fill your home with lush leaves（不是园艺大师也可以把自己的家里装点得绿意盎然）。

don't need的例句：You don't need to be a smoker or a drinker to risk heart disease（并不是只有抽烟喝酒的人才会犯心脏病）；You don't need strength to take part in this sport（参加这项运动不需要太多体力）。