How to Say "certain" in Spanish
The most common Spanish word for “certain” is “seguro” — use 'seguro' when you are asking if someone knows a fact or is confident about something..
seguro
/seh-GOO-roh//seˈɣu.ɾo/
Examples
¿Estás segura de la respuesta?
Are you sure about the answer?
Estoy seguro de que lo vi aquí.
I'm sure that I saw it here.
Es un hombre muy seguro de sí mismo.
He is a very self-confident man.
Always Use 'Estar' for Feeling Sure
To say you feel sure about something, always use the verb 'estar'. For example, 'Estoy seguro' (I am sure). Using 'ser' changes the meaning completely.
Matches the Person or Thing
Like many descriptions in Spanish, 'seguro' must change to match who or what you're talking about: 'seguro' (for masculine singular), 'segura' (feminine singular), 'seguros' (masculine plural), and 'seguras' (feminine plural).
Using 'Ser' instead of 'Estar'
Mistake: “Soy seguro que la tienda está cerrada.”
Correction: Estoy seguro de que la tienda está cerrada. You use 'estar' to talk about a temporary state or feeling, like being sure of something.
cierto
/syerr-toh//ˈθjeɾto/
Examples
La historia que me contó es cierta.
The story he told me is true.
Es un hecho cierto que el sol sale por el este.
It is a certain fact that the sun rises in the east.
No estoy cierto de la hora, déjame revisar.
I'm not sure of the time, let me check.
Position Matters: Use AFTER the Noun
When you want to say something is 'true' or 'certain', 'cierto' comes after the person or thing it's describing. For example, 'una noticia cierta' is 'true news'.
Confusing 'Cierto' and 'Seguro'
Mistake: “Using 'cierto' to talk about feeling safe.”
Correction: 'Cierto' is about facts being true. 'Seguro' is for when you feel sure about something or when something is safe. Say 'Este lugar es seguro' (This place is safe), not 'cierto'.
convencido
kohm-behn-SEE-doh/kombenˈsiðo/
Examples
Ella está convencida de que ganaremos el partido.
She is convinced that we will win the game.
Los científicos están convencidos de la importancia de este descubrimiento.
The scientists are certain of the importance of this discovery.
¿Estás convencido de tu decisión?
Are you sure about your decision?
Agreement is Key
As an adjective, 'convencido' must change its ending to match the person or thing it describes: 'convencido' (masculine singular), 'convencida' (feminine singular), 'convencidos' (masculine plural), 'convencidas' (feminine plural).
Using 'de'
You almost always follow 'convencido' with the word 'de' (of/about) before stating what you are convinced about: 'Estoy convencido de que...' (I am convinced that...).
Forgetting Gender
Mistake: “La jefa está convencido.”
Correction: La jefa está convencida. (The boss is feminine, so the adjective must end in -a.)
determinado
/deh-tehr-mee-NAH-doh//deteɾmiˈnaðo/
Examples
Debes entregar el informe en un día determinado.
You must hand in the report on a specific day.
Bajo determinadas condiciones, el experimento funciona.
Under certain conditions, the experiment works.
Matching the Noun
This word needs to change its ending to match what you are talking about. Use 'determinado' for one male thing, 'determinada' for one female thing, and add an 's' for plurals.
Placement Matters
Mistake: “Using 'determinado' always after the noun.”
Correction: When it means 'certain' or 'some,' it often goes before the noun (e.g., 'determinadas personas'). When it means 'specific,' it usually goes after.
inevitable
ee-neh-vee-TAH-bleh/i.ne.βiˈta.βle/
Examples
Después de tanto esfuerzo, el éxito era inevitable.
After so much effort, success was inevitable.
Cometer errores es una parte inevitable del proceso de aprendizaje.
Making mistakes is an unavoidable part of the learning process.
La lluvia de mañana es inevitable, así que lleva tu paraguas.
Tomorrow's rain is inevitable, so take your umbrella.
Adjective Agreement (The -e ending)
Since 'inevitable' ends in '-e', it doesn't change its ending when describing a masculine or feminine noun. It only changes when describing plural things: 'el cambio inevitable' (masculine singular) and 'la derrota inevitable' (feminine singular).
Making it Plural
To make 'inevitable' describe more than one thing, simply add '-s': 'los problemas inevitables' (the inevitable problems) or 'las verdades inevitables' (the inevitable truths).
Over-agreement
Mistake: “La cosa inevitabla.”
Correction: La cosa inevitable. Remember, adjectives ending in '-e' usually stay the same for both masculine and feminine nouns.
positivo
/poh-see-TEE-voh//posiˈtiβo/
Examples
Necesito una respuesta positiva antes de firmar el contrato.
I need a definite answer before signing the contract.
La ley positiva es aquella que está escrita y establecida.
Positive law is that which is written and established.
tales
/TAH-less//ˈtales/
Examples
El informe debe ser revisado por tales expertos en la materia.
The report must be reviewed by certain experts in the field (meaning 'some specific experts').
Dicen que tales acciones pueden tener consecuencias negativas.
They say that certain actions can have negative consequences.
Se requiere la presencia de tales testigos.
The presence of certain witnesses is required.
Indefinite Reference
In this meaning, 'tales' signals that the noun (e.g., 'experts,' 'actions') is unspecified, perhaps known only to the speaker, acting like the English word 'certain.'
Confusing 'Cierto' and 'Seguro'
Related Translations
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