1You can‘t smoke in the bedrooms.
not加在情态动词后即可
2It doesn't usually snow in winter in Ireland.
没有be动词和情态动词,加助动词,并还原snow
3,don'tPut them on the desk.
祈使句的否定一律加don't
4,She hasn't got brown wavy hair.
完成时里,have 是助动词,可以自身否定
5I don't need to buy any apples.
need在这里不是情态动词,要加助动词否定