How to Say "guaranteed" in Spanish
The most common Spanish word for “guaranteed” is “asegurado” — use 'asegurado' when 'guaranteed' means something is certain to happen or to be in a secure state..
asegurado
/ah-seh-goo-RAH-doh//aseɣuˈɾaðo/

Examples
Revisa que el cinturón de seguridad esté bien asegurado.
Check that the seatbelt is properly secured.
Con tanto esfuerzo, el éxito está asegurado.
With so much effort, success is guaranteed.
Matching the word to the object
This word acts like a describing word. If you are talking about a feminine thing, change the 'o' at the end to an 'a' (asegurada). If it's more than one thing, add an 's' (asegurados).
Asegurado vs. Seguro
Mistake: “Using 'Estoy asegurado' to mean 'I am sure'.”
Correction: Say 'Estoy seguro'. 'Asegurado' usually means you are covered by insurance or physically fastened.
certificado
ser-tee-fee-KAH-doh/seɾ.ti.fiˈka.ðo/

Examples
Hemos comprado café orgánico certificado.
We have bought certified organic coffee.
Envía el paquete por correo certificado para mayor seguridad.
Send the package by registered mail for greater security.
La calidad de este producto está certificada.
The quality of this product is certified/guaranteed.
Agreement is Key
As an adjective, 'certificado' must change its ending to match the noun it describes. Use 'certificada' for feminine nouns (e.g., 'carta certificada') and 'certificados/certificadas' for plural nouns.
Forgetting the Gender Change
Mistake: “Una cuenta certificado (A certified account)”
Correction: Una cuenta certificada. (Since 'cuenta' is feminine, the adjective must end in -a.)
Asegurado vs. Certificado
Related Translations
Learn Spanish with Inklingo
Interactive stories, personalized learning, and more.

