My old high school teacher I had very, very strict.

有。
My old high school teacher was very, very strict.
One of my high school teachers was very, very strict.

old high school 可以是从前的高中，但是my old high school teacher 可能是“我的高中的年纪大的老师”所以，最好是说，one of my high school teachers.除非你现在转到了一所新高中，否则不需要说my old high school.如果真是转了学，就说my previous high school.

很有问题,最大错误是strict是形容词,你怎么拥有它????
你想说以前高中的老师可以用former
old一般指年纪老

我考，说这句英语的人太有才了。

the high school teachers i had was very, very strick.

有问题, 不懂何意思,语法也有错~~~