How come you can sometimes see phrases like “Es broma” or “Es muy linda ciudad”? Why is "un/una" left out?
That's an interesting use of broma. You know that the verb ser does not need an article when the word following is an adjective:
El coche es azul.
Ha sido divertido.
In the case of broma, the word is classified as a noun by the RAE. An example of this usage:
Aquello fue una broma que me gastó mi hermano.
But in such sentences like es broma, that's a fixed expression that uses broma as an adjective. What you are saying is just that what happened has the quality of being a joke. This probably comes from the adverbial expression de broma or en broma. You can say that something es de broma. Dropping the middle preposition en/de is something that has been done at least since the 19th century in Spanish, as seen by some texts found in the CORDE:
—Paz, caballeros —dijo Calpena con gracia—. No me riñan aquí o a los dos les mando a la calle.
—Jugamos, nos divertimos.
Benito Pérez Galdós, "Mendizábal", 1898 (Spain).
This way of adjetivizing a noun (or a expression) is most probably what you see in your second example, es muy linda ciudad.
As stated by the RAE's grammar, what happens with broma also happens with verdad, I would add mentira, both are nouns but you can say es verdad or es mentira.
There are indeed cases in Spanish in which the zero article is used with singular, countable nouns.
The examples at issue can take an indefinite article:
- Es (una) broma.
- Es (una) muy linda ciudad.
(1) seems to be a case in which the countable noun drops the article to become a category, almost as if it were an adjective, as opposed to "ser verdad":
- No es verdad, es broma. (It's not true, it's a joke.)
In (2) the noun "ciudad" seems to be information that is already known. The new information is the adjective phrase "muy linda". A similar case would be:
- Ana es muy linda mujer. (The fact that Ana is a woman is indisputable. I'm just telling you that she's very beautiful.)
It is worth noting that an article can also be used in this case:
3'. Ana es (una) muy linda mujer.
Another example which has just come to mind is, in reference to the gender of a person:
- ¿Es nena o varón? (Is is a girl or a boy?)
In this case, the noun is definitely used as a category, being equivalent to "female or male", and will not usually accept an article.
3.3.5 Omission before singular nouns: general
Un/una is often omitted before singular count nouns. This happens whenever the generic or universal features of the noun are being emphasized. Compare Pepe tiene secretaria 'Pepe’s got a secretary' (like many bosses) and Pepe tiene una secretaria que habla chino 'Pepe’s got a Chinese-speaking secretary'. Section 3.3.6—9 covers some of the cases in which this type of omission occurs.
3.3.6 Not used before professions, occupations, social status, sex
This is a common case of the phenomenon described in 3.3.7: un/una is not used before nouns which describe profession, occupation, social status, and it is often omitted before nouns denoting sex. In this case the noun can be thought of as a sort of adjective that simply indicates a general type:
- Soy piloto/Son buzos I’m a pilot/They’re divers
- Es soltero/Es casada (compare está casada 'she’s married'; see 29.4.1a) He’s a bachelor/She’s a married woman
- Se hizo detective (5) he became a detective
- ...y aunque Alejandra cm mujer... (F. Sébato, Arg.) ...and although Alejandra was a woman...
But nouns denoting personal qualities rather than membership of a profession or other group require the article: compare es negrero 'he is a slave—trader' and es un negrero 'he’s a ”slave-driver”' (I.e. makes you work too hard); es carnicero 'he’s a butcher (by trade)’, es un carnicero 'he’s a butcher (i.e. murderous)’; es Supermán ’he is Superman’, es mi supermán 'he’s a superman'; el sargenta se decía: "No es un ladrón. Es un loco" (M. Vargas Llosa, Pe.) 'the sergeant said to himself "he’s no thief. He’s a madman."'
If a noun of the type discussed above is qualified, it usually become particularized (non—generic) and therefore requires the article. Compare Es actor ’he's an actor’ and Es un actor que nunca encuentra trabajo ’he’s an actor who never finds work’; me han dicho qua usted es un hombre que se ha quedado solo (A. Bryce Echenique, Pe., dialogue) ’they tell me that you are a man who has found himself alone’. But the resulting noun phrase may still be a recognized profession or generic type, so no article will be used: soy profesor de español. See 3.3.9 for discussion. The article is used if it means 'one of...': ' - ¿Quién es ese que ha saludado? — Es un profesor '"Who was that who said hello?" "He’s one of the teachers"'.
3.3.7 Omission of the indefinite article with ser and nouns not included in 3.3.6
Omission of the indefinite article after ser is frequent (a) in certain common phrases, (b) in literary styles: a rare English counterpart is the optional omission of 'a’ with ’part’: 'this is (a) part of our heritage’ esto es (una) parte de nuestro patrimonio. Omission is more common in negative sentences and apparently more frequent in Peninsular Spanish than in Latin-Anmrican. In the following phrases omission seems to be optional, and it produces a slightly more literary style:
- Es (una) coincidencia It's a coincidence
- Es (una) cuestión dc dinero It’s a question of money
- Es (una) víctima dc las circunstancias (S)he's a victim of circumstances
However, no clear rule can be formulated since the article is retained in other common phrases like es una lata (colloquial) ’it’s a nuisance’, es una pena ’it’s a pity’, es un problema ’it’s a problem’, es un desastre ’it/(s)he’s a disaster’, ha sido éxito ’it was a success’. Omission may occur after a negative verb even though it is not usual after the positive verb:
- No es molestia/problema It’s no bother/problem
- No es exageración It’s no exaggeration
- No as desventaja It’s not a disadvantage
In other cases, omission often, but not always, produces a literary effect:
- La codorniz es # ave tiernísima (M. Delibes, Sp.) The quail is an extremely tender bird (to eat)
- Es # mar de veras (M. Vargas Llosa, Pe. dialogue) It’s (a) real sea
- ¡Éstá/Esta es # cuestión que a ustedes no les importa!* (J. Ibargüengoitia, Mex, dialogue) This is an affair that has nothing to do with you!
In all the above examples the appropriate gender of un or una could have been used at the points marked with #, but the original texts do not use the article.
(i) If the following noun is not generic but merely implies the possession of certain qualities un/una must be used: el hombre es un lobo para el hombre ’man is a wolf to man’ (but. not a member of the wolf species), Mercedes es un terremoto ’Mercedes is an earthquake’ (ie. a hell—raiser), está hecho una foca ’he’s got really fat’ (la foca = ’seal’—the animal).
(ii) Omission of the indefinite article before a qualified noun tends to produce an archaic or heavily literary effect (or it makes the sentence sound like stage instructions), as in entra una señora con sombrero verde con plumas de avestruz ’a lady with a green hat with ostrich feathers comes in’, where un sombrero verde would nowadays be much more normal. Where Unamuno wrote, in the early 20th century, era un viejecillo [...] con levitón de largos bolsillos ’he was a little old man in a large frock-Coat with deep pockets’, a modern writer might prefer un levitón.
NB: In formal literary styles, omission of un/una is normal in definitions when the subject comes first: *novela es toda obra de ficción que... 'a novel is any work of fiction that...'.
Lo explicaré en español.
Se omite "un/a" generalmente en el lenguaje coloquial para que genere globalidad al asunto. "Es una broma" quiere aclarar que puede usarse "Perdona, solo es una broma" o "Lo siento, es una broma"; y en el caso de "Es broma" sería lo mismo pero cambiaría la forma de verse, por ejemplo: "Es broma, ¿verdad? " o "¿Lo que me dices es broma?", "¡Que es broma¡".
La segunda frase tendría más sentido como "Es muy linda la ciudad" o "La ciudad es muy linda", pero como he dicho se usa mejor en lenguaje coloquial.