How is this following sentence in DIRECT speech incorrect?

In the given sentence, the name is not capitalized outside the inverted commas or also known as the quotation marks. John is a proper name thus the first letter should be a capital letter and as a general rule, all sentences should start with a capital letter.

So even if a common noun is used, for example, a boy or the boy, it should be written as A boy or The boy and continue with the rest of the sentence. The inverted commas should also be the same if you write the first inverted comma as “, it should be ended with “ also.