给定一篇包含错误的文章，指出其中所有的语法错误。


"When I was walking down the street, I seen a black cat cross my path. I don't believe in superstitions but it was creepy."
"When I was walking down the street, I **saw** a black cat cross my path. I don't believe in superstitions**;** but it was creepy." 

语法错误： 
1. seen应改为saw。 
2. 句末需要加上分号或句号。