How to Say "complex" in Spanish
The most common Spanish word for “complex” is “complejo” — use 'complejo' as an adjective when describing something that is difficult to understand, analyze, or explain..
complejo
/kom-PLE-ho//komˈplexo/
Examples
Resolver este problema matemático es muy complejo.
Solving this math problem is very complex.
La situación política se ha vuelto más compleja en las últimas semanas.
The political situation has become more complicated in recent weeks.
Ella tiene una personalidad compleja, nunca sabes lo que piensa.
She has a complex personality, you never know what she's thinking.
El complejo deportivo tiene una piscina olímpica y varias canchas de tenis.
The sports complex has an Olympic pool and several tennis courts.
Adjective Agreement
As an adjective, 'complejo' must match the thing it describes. If the thing is feminine (like 'situación'), it becomes 'compleja'. If it's plural (like 'problemas'), it becomes 'complejos'.
Always Masculine
When used as a noun meaning a group of buildings, 'complejo' is always masculine, so you always use 'el' or 'un' before it.
Using 'Tener'
To express that someone has a psychological complex, you use the verb 'tener' (to have): 'Tengo un complejo' (I have a complex).
Confusing Complexity and Difficulty
Mistake: “Using 'difícil' when you really mean 'complejo'.”
Correction: 'Difícil' just means 'hard to do'. 'Complejo' means 'made of many parts'. While complex things are often difficult, use 'complejo' when you want to emphasize the structure.
complejo
/kom-PLE-ho//komˈplexo/
Examples
El complejo deportivo tiene una piscina olímpica y varias canchas de tenis.
The sports complex has an Olympic pool and several tennis courts.
Resolver este problema matemático es muy complejo.
Solving this math problem is very complex.
La situación política se ha vuelto más compleja en las últimas semanas.
The political situation has become more complicated in recent weeks.
Ella tiene una personalidad compleja, nunca sabes lo que piensa.
She has a complex personality, you never know what she's thinking.
Adjective Agreement
As an adjective, 'complejo' must match the thing it describes. If the thing is feminine (like 'situación'), it becomes 'compleja'. If it's plural (like 'problemas'), it becomes 'complejos'.
Always Masculine
When used as a noun meaning a group of buildings, 'complejo' is always masculine, so you always use 'el' or 'un' before it.
Using 'Tener'
To express that someone has a psychological complex, you use the verb 'tener' (to have): 'Tengo un complejo' (I have a complex).
Confusing Complexity and Difficulty
Mistake: “Using 'difícil' when you really mean 'complejo'.”
Correction: 'Difícil' just means 'hard to do'. 'Complejo' means 'made of many parts'. While complex things are often difficult, use 'complejo' when you want to emphasize the structure.
complejo
/kom-PLE-ho//komˈplexo/
Examples
Tiene un complejo de inferioridad porque siempre se compara con su hermano.
He has an inferiority complex because he always compares himself to his brother.
Resolver este problema matemático es muy complejo.
Solving this math problem is very complex.
La situación política se ha vuelto más compleja en las últimas semanas.
The political situation has become more complicated in recent weeks.
Ella tiene una personalidad compleja, nunca sabes lo que piensa.
She has a complex personality, you never know what she's thinking.
Adjective Agreement
As an adjective, 'complejo' must match the thing it describes. If the thing is feminine (like 'situación'), it becomes 'compleja'. If it's plural (like 'problemas'), it becomes 'complejos'.
Always Masculine
When used as a noun meaning a group of buildings, 'complejo' is always masculine, so you always use 'el' or 'un' before it.
Using 'Tener'
To express that someone has a psychological complex, you use the verb 'tener' (to have): 'Tengo un complejo' (I have a complex).
Confusing Complexity and Difficulty
Mistake: “Using 'difícil' when you really mean 'complejo'.”
Correction: 'Difícil' just means 'hard to do'. 'Complejo' means 'made of many parts'. While complex things are often difficult, use 'complejo' when you want to emphasize the structure.
complicado
/kom-pli-KAH-doh//kompliˈkaðo/
Examples
Este problema de matemáticas es muy complicado.
This math problem is very complicated.
La instalación del programa fue más complicada de lo que pensaba.
The program installation was more complicated than I thought.
Agreement Rule
As an adjective, 'complicado' must change its ending to match the noun it describes: 'un problema complicado' (masculine singular), 'una tarea complicada' (feminine singular), 'los pasos complicados' (masculine plural).
Forgetting the Feminine Form
Mistake: “La situación es complicado.”
Correction: La situación es complicada. (The noun 'situación' is feminine, so the adjective must end in -a.)
oscuro
oh-SKOO-roh/osˈkuɾo/
Examples
El autor tiene un estilo de escritura muy oscuro, difícil de seguir.
The author has a very obscure (or complex) writing style, difficult to follow.
La historia de su pasado es bastante oscura y nadie sabe la verdad.
The story of his past is quite obscure/vague, and nobody knows the truth.
Las oscuras motivaciones del villano nunca fueron claras.
The villain's obscure motivations were never clear.
Figurative Use
When 'oscuro' refers to difficulty or complexity, it describes abstract ideas (like a concept, a memory, or an intention) instead of just physical spaces. It keeps the same agreement rules as the literal meaning.
Complejo vs. Complicado
Related Translations
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