I start working at this company when I left school这句话有什么语法错误,怎么改?如果不去掉"when"要怎么修改,

I start working at this company when I left school这句话有什么语法错误,怎么改?如果不去掉"when"要怎么修改,
I start working at this company when I left school这句话有什么语法错误,怎么改?
如果不去掉"when"要怎么修改,

I start working at this company when I left school这句话有什么语法错误,怎么改?如果不去掉"when"要怎么修改,
work可用作名词,也可用作动词.
当用作名词时,只需改时态：
I started work at this company when I left school.
当用作动词时,后面可以加to,也可以把后一个动词变为动名词形式.即：
I started working at this company when I left school.或 I started to work at this company when I left school.
when不能换为since,如果换了,时态就更得变.
用作名词时为：I have/had started work at this company since I left school.

用作动词时为：I have/had started working at this company since I left school.或 I have/had started to work at this company since I left school.