The Personal "A" - When To Use and When Not To Use?

Question

How do you know when to put an "A" at the beginning of a sentence when mentioning someone's name? Sometimes there is an A and sometimes there isn't. What makes it required?

Answer 1

Perhaps this lesson will help, it refers to many uses of the spanish 'a' but the personal 'a' in section 5 may be what you're looking for.

Answer 2

[Try looking at this from the SD reference section1