ihavebeenteachingsince10yearsago为什么teach要加ing那是以进步行时been 后动词要加的呀

ihavebeenteachingsince10yearsago为什么teach要加ing那是以进步行时been 后动词要加的呀
ihavebeenteachingsince10yearsago为什么teach要加ing
那是以进步行时been 后动词要加的呀

ihavebeenteachingsince10yearsago为什么teach要加ing那是以进步行时been 后动词要加的呀
have been doing为现在完成进行时态,表主动动作,即从过去某一时间开始一直持续进行到现在为止的动作,还有可能继续进行下去,如：The building has been completed.大楼已经被盖好了.They have been building the hall.他们一直在建造着那所礼堂.(表主动动作,该动作尚未停止,只有延续性动词才能用于此种时态,而have been done无此限制,但必须是及物动词才能用于被动语态).