grammar - Starting a Sentence with a Conjunction

My high school English teacher taught us to never start a sentence with conjunctions, but throughout the years I have seen a lot of such usage in academic writings and novels. I have also read various articles, saying that such usage is now acceptable. Is it merely a preference of style or is it grammatically wrong? Does it otherwise imply different semantics from the usage that follows a comma(,)?

For example, are the following sentences acceptable in terms of grammar/formality?

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  "The organization should have taken the blame. Or, its leader can sacrifice himself for the well-being of all."

  
  


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  "She is one of a kind – she displays high empathy on each and every strangers she meets. But, she lives in a fiction."

  
  


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  "The city is wondrous, in spite of its proximity to my hometown. And, a highly regarded culture resides there."

  
  

Thanks in advance.

Answer

Coördinating conjunctions, such as and, or and but, can be used to begin a new sentence. This was already widely accepted in Fowler's time, and probably always. There is nothing wrong with the conjunctions in your examples. In general, though, you should apply this feature of our language judiciously: do not do it in every other sentence.

However, you should not use a comma after such conjunctions the way you did. Some authors use commas there, but be prepared for some criticism; it looks very casual. The exception is when what follows is parenthetical, such as in this sentence:

But, even though I like her, I must leave now.

The clause even though I like her is marked off by commas, the first of which happens to come after but.

You can always begin a sentence with a subordinating conjunction, such as because, although, etc., provided that the subordinate clause is attached to a main clause. If you don't attach it to a main clause, it becomes less formal, which may or may not be appropriate, depending on the genre.