oh,that was probably when I was seeing the doctor!when I was seeing the doctor在句子中充当什么成分?

oh,that was probably when I was seeing the doctor!when I was seeing the doctor在句子中充当什么成分?
oh,that was probably when I was seeing the doctor!
when I was seeing the doctor在句子中充当什么成分?

oh,that was probably when I was seeing the doctor!when I was seeing the doctor在句子中充当什么成分?
这句是主系表结构,when引导的是表语从句.

宾语从句

when I was seeing the doctor是表语从句