Cambiar vs. alterar vs. modificar
The Spanish words 'cambiar', 'alterar', and 'modificar' all have similar meanings relating to changing or altering something. However, they are used in different contexts and have slightly differing connotations.
Cambiar
This verb generally means ‘to change’ and is used in a broad range of contexts referring to a complete, often tangible transformation where the end result is different from the initial state.
Voy a cambiar mi coche por uno nuevo.
(I'm going to change my car for a new one.)
Necesitas cambiar tu actitud si quieres tener éxito.
(You need to change your attitude if you want to be successful.)
Ella cambió su ropa después del entrenamiento.
(She changed her clothes after training.)
Alterar
'Alterar' can be translated as ‘to alter’. It often implies an internal or emotional change or disturbance, but can also signify changing an object or situation so as it's noticeable but not wholly distinguishable from its original form.
La noticia alteró el humor de todos en la sala.
(The news altered everyone's mood in the room.)
No alteres los planes sin consultar conmigo primero.
(Don't alter the plans without consulting me first.)
La contaminación puede alterar el equilibrio del ecosistema.
(Pollution can alter the balance of the ecosystem.)
Modificar
'Modificar' is the equivalent of ‘to modify’. It implies making adjustments or changes to something without necessarily turning it into something else. Usually these changes are smaller, more specific adjustments rather than a complete overhaul.
Quiero modificar el diseño de mi página web.
(I want to modify the design of my web page.)
Es posible que tengamos que modificar nuestros planes debido al clima.
(We may have to modify our plans because of the weather.)
Necesitamos modificar nuestra estrategia de marketing.
(We need to modify our marketing strategy.)
Summary
'Cambiar', 'alterar', and 'modificar' all have similar meanings related to change, but distinct connotations and uses. 'Cambiar' refers to a complete transformation, 'alterar' often describes emotional changes or subtle physical changes, while 'modificar' suggests smaller adjustments rather than a total transformation.