last came here 语法对不对?

How long has it been since he last came here?
How long has it been since he came here last time
两个句子,是不是都对呢?第一句,不确定,last 放在 came 前面 这么写 ,语法上对不对?
是的,多对.
析：last还可以作副词.常放在实义动词前面:
3) ADV:ADV with v If something last happened on a particular occasion,that is the most recent occasion on which it happened.
When were you there last?...
The house is a little more dilapidated than when I last saw it...
Hunting on the trust's 625,000 acres was last debated two years ago.
追问
有一个句子 咨询下您的看法
1 How long haven't you come here 您觉得这么说,对不.
否定的完成时 疑问句,这里能用短暂动词 come
答：短暂性动词的否定表状态可以用于现在完成时的延续性用法.
但这句话本身有逻辑错词,一如：I don't know you are here.一样.当我说这话时,你已经在这里了,不能说我现在还不知道,也不能问你有多久没来这里了?
所以要换一个例句,问：How long hasn't he come here?这个句子,我认为是语法、逻辑都正确的.
2 他多久没洗澡了?（ 如果是您,会怎么翻译这句）谢谢
你这句是将我给你的网络例句翻译成汉语的结果吧?
How long hasn't he bathed?/had a shower?