In spanish you also have to use a/an:

Es un perro (its a dog)

Saying "es perro" makes no sense.

The problem is that you are mixing two different constructs, if you are refering to the whole thing you have to say un/una, if you are describing a property of something you don't use it.

Es un perro, es macho. (It's a dog, is male)

If you are talking about doctor being a property of someone,like his profession, you say "es médico" but if you are refering to the doctor as an entity and not a property of someone you have to use "a":

Es un médico muy famoso (He is a very famous doctor). "Es médico muy famoso" again makes no sense.

It’s simply that, in English, there is no indefinite plural article — or, equivalently, that the indefinite plural article is null. So ‘they are doctors’ is consistent with the behaviour of plural nouns elsewhere.

Contrast this with, for example, French, where the indefinite singular un(e) correspond to the indefinite plural des: La boulangerie vend des baguettes ‘the bakery sells baguettes’ (whereas English cannot say *‘a baguettes’). But as in Spanish, professions take no article either way: Il est médecin / Ils sont médecins. So all three languages are self-consistent, just in their own ways.

English would work for titles:

He is President.

He is Doctor. (Dr.)

"He is president" is different than "he is a president" (one among many) or "he is the president" (the one specific).

But it would have to be within the context of titles

With the specific case, the "the" could be dropped - "who is in running this rpg?" points "he is gamesmaster" which means "he is the gamesmaster".

Probably because it's a role, similar to the title?

You should not look at superficial similarities between languages, but at logic.

To the question: "What is he?", the answer can be "He is married, tall, doctor in medicine".

On another point of view, "He is a doctor" = "one in the set of the doctors". (But which one of the crowd there? The tall one is the doctor.)

"He is doctor in medicine": identity; "He is a doctor": aside property.

With different expressions, you are not expressing the same thing, but different ideas (some of them more preponderant in use in a territory).

Interstingly it is the same in german, you would say "Er ist Arzt" not "Er ist ein Arzt". Which makes me wonder why english uses an indefinite article there, since it doesn't seem to be either germanic or romantic in origin.

And actually, it is not so common to write the actual personal pronouns in Spanish, as they become more or less clear seeing the verb ending, due to conjugation of the verb. So one would probably say "Es médico.", when in context.

Certainly English can be odd. It can usually be understood through tough thorough thought though.

You are right most of the time for English, but today that should be "Arrr! He be the sawbones".

Spain had pirates too, but I don't speak Spanish so had to ask an LLM. It suggested that today in Spanish it would be "Él es el matasanos del barco". Any authentic Spanish pirates who can verify or correct that?

There’s an ongoing debate about whether articles are a proper part of speech; the only articles in English are the and a. Some grammarians prefer “determiner”, which includes a, the, some, other, no (as in “no man”) etc. A determiner is just a word that selects/determines an element of a larger assumed universe of discourse.

Some grammarians deny the existence of determiners, as they are not found in traditional grammars of the language, with the words now considered determiners placed in other parts of speech.

The further back you go in Indo-European languages, they don't have articles. It's a relatively recent innovation.

So for example latin didn't have them. Eventually they evolved from ille and unus.

Much of Eastern Europe still does not have articles.

You can say "they are the doctors" -- but yeah it's a slightly different meaning.

BTW in German, it's a fun distinction. The old "ich bin (ein) Berliner". (or hamburger or frankfurter...)

There is no plural equivalent of a/an. So where you would use a/an becomes no-article for plural nouns.

I suppose you could say, “they are both doctors” or “they are all doctors.”

Those sound fine to me, depending on context.

> Singular: "He is a doctor." Plural: "They are doctors."

Here the 'a' is shifting position to become the world final 's'

Over-learning Portuguese (as a beginner) almost make me feel that "He is a doctor" should become "They are as doctors".

il est docteur

vs

c'est un docteur

In "They are doctors" the 'they' is the subject and you don't need articles. 'They' is plural.

But in "The doctors are female" you do because the subject is some specific group of doctors. It's singular because its a single group of things.

Is French different? Il est un médecin? Il est médecin? Ils sont médecins sounds fine.