What are Indefinite Adjectives?
Spanish indefinite adjectives are words that refer to non-specific quantities, amounts, or identities. They help express concepts like "all," "another," "each," "some," or "no" without being precise about exactly what or how many.
These adjectives must agree with the gender and number of the noun they modify, and they're essential for expressing vague or general quantities in Spanish.
Examples
Todo estudiante debe estudiar.
Every student must study.
Necesito otra oportunidad.
I need another opportunity.
Cada día es diferente.
Each day is different.
Todo (All, Every, Whole)
Todo means "all," "every," or "whole." It's one of the most versatile indefinite adjectives and agrees in gender and number with the noun it modifies.
Forms of Todo
Todo has four forms that agree with the noun:
Todo Forms
| Pronoun | Conjugation | English |
|---|---|---|
| Masculine singular | todo | all/every/whole (masc. sing.) |
| Feminine singular | toda | all/every/whole (fem. sing.) |
| Masculine plural | todos | all/every (masc. pl.) |
| Feminine plural | todas | all/every (fem. pl.) |
todo el mundo
everybody, everyone
toda la noche
all night
todos los días
every day
todas las semanas
every week
Usage with Articles
Todo is usually followed by a definite article (el, la, los, las) when it means "all" or "whole":
Trabajé todo el día.
I worked all day.
Toda la clase estudió.
The whole class studied.
Todos los estudiantes llegaron.
All the students arrived.
Otro (Other, Another)
Otro means "other" or "another." It never uses an indefinite article (un/una) before it - this is a common mistake for English speakers.
Forms of Otro
Otro agrees with the gender and number of the noun:
Otro Forms
| Pronoun | Conjugation | English |
|---|---|---|
| Masculine singular | otro | another/other (masc. sing.) |
| Feminine singular | otra | another/other (fem. sing.) |
| Masculine plural | otros | other (masc. pl.) |
| Feminine plural | otras | other (fem. pl.) |
otro libro
another book
otra vez
another time, again
otros países
other countries
otras personas
other people
Common Mistake with Otro
⚠️ Never use un/una with otro!
❌ Incorrect: *un otro libro*
✅ Correct: otro libro
This is different from English, where we say "another book" (a + n + other).
Quiero otro café. (NOT: un otro café)
I want another coffee.
Dime otra historia. (NOT: una otra historia)
Tell me another story.
Cada (Each, Every)
Cada means "each" or "every." Unlike other indefinite adjectives, cada is invariable - it never changes form regardless of gender or number.
Cada - Invariable Form
Cada is always the same, whether the noun is masculine, feminine, singular, or plural:
cada día
each/every day
cada semana
each/every week
cada dos horas
every two hours
cada uno de nosotros
each one of us
Cada vs Todo
Cada emphasizes individual items, while todo emphasizes the group as a whole:
Cada = emphasis on individual items
Todo = emphasis on the complete set
Cada estudiante tiene un libro.
Each student has a book. (individual focus)
Todos los estudiantes tienen libros.
All students have books. (group focus)
Alguno (Some, Any)
Alguno means "some" or "any" in affirmative and interrogative sentences. It has special forms and undergoes apocope (shortening) before masculine singular nouns.
Forms of Alguno
Alguno agrees with gender and number, with a special shortened form:
Alguno Forms
| Pronoun | Conjugation | English |
|---|---|---|
| Masculine singular (before noun) | algún | some/any (masc. sing.) |
| Masculine singular (standalone) | alguno | some/any (masc. sing.) |
| Feminine singular | alguna | some/any (fem. sing.) |
| Masculine plural | algunos | some/any (masc. pl.) |
| Feminine plural | algunas | some/any (fem. pl.) |
algún día
some day
alguna vez
sometime, ever
algunos libros
some books
algunas personas
some people
Apocope with Algún
Before masculine singular nouns, alguno becomes algún (loses the final -o):
Algún estudiante llamó.
Some student called.
¿Tienes algún problema?
Do you have any problem?
En algún momento lo haré.
At some point I'll do it.
Ninguno (No, Not Any, None)
Ninguno means "no," "not any," or "none." It's the negative counterpart of alguno and also undergoes apocope before masculine singular nouns.
Forms of Ninguno
Ninguno follows the same patterns as alguno:
Ninguno Forms
| Pronoun | Conjugation | English |
|---|---|---|
| Masculine singular (before noun) | ningún | no/not any (masc. sing.) |
| Masculine singular (standalone) | ninguno | no/not any (masc. sing.) |
| Feminine singular | ninguna | no/not any (fem. sing.) |
| Masculine plural | ningunos | no/not any (masc. pl.) |
| Feminine plural | ningunas | no/not any (fem. pl.) |
No tengo ningún problema.
I don't have any problem.
Ninguna persona vino.
No person came.
No hay ningunos libros aquí.
There are no books here.
Double Negative with Ninguno
In Spanish, ninguno is used with the negative no to create a double negative, which is grammatically correct:
No vi a ningún estudiante.
I didn't see any student.
No tengo ninguna pregunta.
I don't have any questions.
Ninguno de ellos vino.
None of them came. (no "no" needed when ninguno starts the sentence)
Summary and Usage Tips
Here's a quick reference for using indefinite adjectives correctly:
Agreement Rules:
- Todo, otro, alguno, ninguno: agree in gender and number
- Cada: invariable (never changes)
Special Forms:
- Alguno → algún (before masculine singular nouns)
- Ninguno → ningún (before masculine singular nouns)
Common Expressions:
Examples
todo el tiempo (all the time)
all the time
otra vez (again)
again
cada vez más (more and more)
more and more
alguna vez (ever, sometime)
ever, sometime
de ninguna manera (no way)
no way