since主句中带的动词时延续性还是瞬间性

这里since是自从…以来的意思
接一段时间 + ago：如 They have lived in that house since two years ago.要求：谓v.用现在完成时,而且须是延续性动词.
接时间状语从句：如 I have loved her since I met her last time./ Lily has stayed at home since she left school.要求：主句的谓v.用现在完成时,而且须是延续性动词；从句的谓v.用一般过去时,而且须是终止性动词

since 自某一刻起，至今 .......

my friend died last week. 上星期死了.不能用since。可以说
A week has passed since my friend died. 从我朋友去世，一周过去了。

since my father died ？ 自从父亲死（那一刻）算起

my friend died since last week(错误)
My friend has been dead since last week.（正确）
由since+过去时间点，作时间状语的句子的时候主句应该用现在完成时。
It's +一段时间+since+过去时间点，是一个固定搭配，表示“自从……到现在有……时间了。”
如果有疑问，欢迎追问，
如果...