I am struggling with using articles in noun clauses. I have seen some examples where an articles is omitted when the following noun is not even uncountable. For example:
"Tim Courtney, chief investment officer of Exencial Wealth Advisors, said: 'We're stockpiling commodities and demand is not picking up. It's kind of a depressing market.'"
Would it be correct if I write " Time Courtney, a chief investment officer of Exencial Wealth Advisors,..." with an article. I do not believe the word "officer" is uncountable.
Another example to further explain my problem: Mr. Smith, a teacher at Lincoln high school, has a phD degree in math. or Mr. Smith, teacher at Lincoln high school, has a phD degree in math.
Which one is grammatically correct? Or are both acceptable? or they simply carry different meanings.
Please help. Thank you.