什么样的词过去式双写最后字母再加ed的?我不需要不规则变化的,我需要的词就如cancel----cancelled

重读闭音节单词需双写最后一个辅音字母再加-ed。
例： stop
plan
fit stopped
planned
fitted stopped [stCpt]
planned [plAnd]
fitted [5fitid]
以-r音节结尾的词，双写r字母，
再加-ed prefer
refer preferred
referred preferred [prI`f:d]
referred [ri5fE:]

stop plan fit refer prefer cancel travel quarrel[最后两个可加可不加]