past perfect continuous tense??

[Unregistered]

a) He had been seeing his doctor for a number of years before the accident.

(b) he had seen his doctor for a number of years before the accident.

What is the difference?

 

[Raymott]

a) He had been seeing his doctor for a number of years before the accident.

(b) he had seen his doctor for a number of years before the accident.

What is the difference?

I'd only use a. with "for a number of years".
You could say, "He had seen his doctor only three times before the accident." With "only three times" you wouldn't use "He had been seeing".

"had been seeing" for a period of time.
"had seen" a number of times.