I found this sentence:
Before he became a writer , Conan Doyle studied medicine, and much of the character is taken from...
However, according to the article (please, see below) - I would say that there should be past perfect instead of past simple. What do you think? Is it the same construction which calls for past the perfect only?
Thank you very much :)
If the Past Perfect is not referring to an action at a specific time, Past Perfect is not optional. Compare the examples below. Here Past Perfect is referring to a lack of experience rather than an action at a specific time. For this reason, Simple Past cannot be used.
She never saw a bear before she moved to Alaska. Not Correct
She had never seen a bear before she moved to Alaska. Correct