Using and omitting articles

Me pongo la chaqueta. Hoy es lunes. Necesito medio kilo de arroz.I'm putting on my jacket. Today is Monday. I need half a kilo of rice.

By now you know the forms — definite articles (el/la/los/las) and indefinite articles (un/una/unos/unas) — and a few everyday cases where Spanish and English part ways: generic nouns and body parts need el/la in Spanish, and a plain profession, otro, and qué exclamations drop un/una. This lesson rounds out that picture with the everyday cases those two lessons didn't cover yet.

Quick shortcut: Spanish often prefers the definite article with clothing, the way it does with body parts (la chaqueta), when whose clothing it is is obvious. Hoy es lunes has no article, but a routine needs one: los lunes. cien, mil and medio already mean "a/one hundred", "a/one thousand" and "half a" — no un/una in front of them.

Clothing often uses the definite article when the owner is clear

Definite articles already showed that Spanish uses el/la/los/las with body parts where English uses a possessive (Me duele la cabeza). The same pattern is common with clothing too, when it's obvious from context whose clothing it is — though unlike with body parts, the possessive is still perfectly grammatical here, and is needed for emphasis or contrast:

• Me pongo la chaqueta. (I'm putting on my jacket.)
• Quítate los zapatos. (Take off your shoes.)
• Lleva la camisa sucia. (He's wearing his dirty shirt.)
• but Me pongo mi chaqueta, no la tuya. (I'm putting on my jacket, not yours — the possessive comes back for contrast)

Telling the day versus talking about a routine

Naming what day it is, right after ser, takes no article at all:

• Hoy es lunes. (Today is Monday.)
• Mañana es sábado. (Tomorrow is Saturday.)

But talking about something that happens on a given day, as a habit, needs the definite article — los + the day, covered in full in adverbs of frequency:

• Los lunes tengo clase de español. (On Mondays I have Spanish class.)
• Trabajamos los sábados. (We work on Saturdays.)

Cien, mil and medio: already mean "a"

A small group of words already carry their own "a/an" meaning, so un/una doesn't go in front of them:

medio agrees in gender with the noun (medio kilo / media hora); mil never changes, and cien doesn't either — except it becomes ciento right before another number (ciento uno, ciento veinte).

cierto/cierta ("a certain") and tal ("such a") work the same way when they introduce a vague, unspecified reference by themselves — no un/una needed:

• Cierta persona me lo dijo. (A certain person told me.)
• Nunca dije tal cosa. (I never said such a thing.)

This isn't an absolute rule for these two, though — un cierto hombre and un tal Juan are also correct, with a slightly different nuance ("a certain man [I won't name]", "a man called Juan"). Without un/una, they're the simpler, more common everyday phrasing.

Common mistakes

• ❌ Hoy es el lunes. → ✅ Hoy es lunes. (no article when ser simply names the day)
• ❌ Cuesta un cien euros. → ✅ Cuesta cien euros. (cien already means "a hundred" — no un in front)
• ❌ Espera una media hora. → ✅ Espera media hora. (medio/media already means "half a" — no un/una in front)

Quick check

Fill in the blank, or write "—" if no article is needed:

1. Me pongo ___ zapatos. (my shoes)
2. Hoy es ___ martes. (stating the day)
3. ___ sábados no trabajo. (on Saturdays, as a routine)
4. Necesito ___ medio litro de leche.
5. Cuesta ___ mil pesos.

Key takeaways

• Clothing often takes the definite article, the way body parts do, when the owner is obvious: Me pongo la chaqueta. The possessive is still grammatical and comes back for emphasis or contrast.
• Naming the day right after ser takes no article (Hoy es lunes); a habitual "on ___s" needs los + the day (Los lunes trabajo).
• cien, mil and medio/media already carry an "a/an" meaning and don't take un/una in front of them; medio agrees in gender (medio kilo / media hora); mil never changes, and cien becomes ciento right before another number (ciento veinte).
• cierto/cierta and tal work the same way when introducing a vague reference on their own (cierta persona, tal cosa) — but unlike cien/mil/medio, un cierto hombre and un tal Juan are also correct, with a different nuance.