TLDR: This question is about vocatives. Is there a rule to explain how to know whether you can drop a person’s name when addessing someone just by their title alone, or whether that form is expressly forbidden by some mystery grammar? I’m looking for some veiled grammatical explanation if there is one.
Consider how this group:
- Senator Smith
- Governor Smith
- Minister Smith
- Doctor Smith
- Vicar Smith
- Father Smith
- Sheriff Smith
- Judge Smith
- Nurse Smith
- Professor Smith
Contrasts with this group:
- King Jones
- President Jones
- Pope Jones
- Lord Jones
- Chief Justice Jones
- Speaker Jones
When it comes to how they’re directly addressed, with the Smiths you can drop the Smith part when you address them and it still sounds alright, albeit somewhat familiar of course:
- Doctor Smith, the patient will see you now.
- Doctor, the patient will see you now.
- Senator Smith, your vote today is critical.
- Senator, your vote today is critical.
But with the Joneses, you can’t seem to get away with that at all:
- President Smith, the Republic will not long survive such good fortune.
- *President, the Republic will not long survive such good fortune.
- Mister President, the Republic will not long survive such good fortune.
- King Smith, the peasants are revolting.
- *King, the peasants are revolting.
- Your Majesty, the peasants are revolting.
For whatever reason, the Joneses seem to demand more “little empty words” in direct address than the Smiths do: Why is that?
Some of the Joneses get a Mister/Madame like Mister Chief Justice or Madame Speaker, while others get fanciful indirect forms from days of old like My Lord or Your Majesty or Your Holiness, and all the rest.
In some cases, it feels like you can only drop the name if the remaining title still applies for you. So Tommy Smith can call his Uncle Smith just plain Uncle, but it doesn’t feel right for someone who isn’t his uncle to do so; he’s Tommy’s uncle, not your own.
Why does the grammar differ here?
What’s the rule for knowing whether can just drop the name and keep the title in vocative use?
Alternately phrased, what’s the rule for knowing whether you have to either add more words like Mister if you drop the name?
Are these all actually in the same word-class?