Mr. Smith had a big house in dowrtowm.是过去时吗 怎么区分

时态看谓语动词。这句话的谓语动词是had,是have的过去式,所以是过去时 再问： My mother usually cut the meat into piece。改为否定，一般疑问句 再答： 这句话的cut是过去式，因为my mother 是第三人称单数，后面的谓语动词不会用原形，只能是三单或过去式。而cut不是三单，只能是过去式 否定 My mother didn't usually cut the meat into pieces。 一般疑问 Did your mother usually cut the meat into pieces?