Destructivo vs. destructor
While both destructivo and destructor translate to destructive or related concepts in English, there is a grammatical and nuance difference. Generally, destructivo describes the quality, nature, or negative potential of something (often abstract), whereas destructor usually refers to the active agent or physical entity that is performing the destruction (often used as a noun meaning destroyer).
Destructivo
B1This is an adjective used to describe something that causes damage, has a negative influence, or possesses the capability to ruin. It is frequently used for abstract concepts like behaviors, criticism, habits, or relationships.
Su comportamiento celoso se volvió muy destructivo para el matrimonio.
(His jealous behavior became very destructive for the marriage.)
No debes escuchar las críticas destructivas de personas envidiosas.
(You should not listen to the destructive criticism of envious people.)
El poder destructivo de esa bomba es incalculable.
(The destructive power of that bomb is incalculable.)
Tenemos que romper este ciclo destructivo antes de que sea tarde.
(We have to break this destructive cycle before it is too late.)
Fumar es un hábito destructivo para la salud.
(Smoking is a destructive habit for one's health.)
Destructor
B2This word functions as both an adjective and a noun. It refers to the specific agent, person, machine, or force that effectively destroys. When used as an adjective, it implies that which destroys.
El fuego destructor consumió varias casas en el vecindario.
(The destructive fire consumed several houses in the neighborhood.)
En la película, el robot era una máquina destructora imparable.
(In the movie, the robot was an unstoppable destroying machine.)
Necesitamos un destructor de papel para estos documentos confidenciales.
(We need a paper shredder (destroyer) for these confidential documents.)
El virus actúa como un agente destructor de las células sanas.
(The virus acts as a destructive agent against healthy cells.)
El ejército envió un destructor para patrullar la costa.
(The army sent a destroyer (warship) to patrol the coast.)
Summary
To choose the right word, ask yourself if you are describing a quality or an agent. Use destructivo when describing the nature or effect of something, especially abstract concepts like criticism or habits. Use destructor when referring to the specific entity (person, machine, or force) that is actively doing the destroying, or when using the noun destroyer.