im·per·fectBrE/ɪmˈpɜːfɪkt/NAmE/ɪmˈpɜːrfɪkt/nounthe imperfect (also the imˌperfect ˈtense) [sing.](grammar语法) theverbtensethatexpressesactioninthepastthatisnotcomplete. Itisoftencalledthepastprogressiveorpastcontinuous.过去未完成时（常称为过去进行时）◆In'whileIwaswashingmyhair', theverbisintheimperfect. while I was washing my hair 中的动词是过去未完成时。