at a time,at times,at onetime,sometime,sometimes分别是什么意思?

at a time,at times,at onetime,sometime,sometimes分别是什么意思?
at a time,at times,at onetime,sometime,sometimes分别是什么意思?

at a time,at times,at onetime,sometime,sometimes分别是什么意思?
at a time＝曾经的某一次
at times＝时常
at one time＝曾经
sometime=将来或过去的某时
sometimes=有时 ,几次

at a time＝一次
at times＝每当
at onetime＝有一次
sometime=某时
sometimes=有时

at times=sometimes意思是有时 sometime是某时
at a time和at onetime我没听说过.