How to Say "lifelong" in Spanish
The Spanish word for “lifelong” is “perpetuo” — B1 level.

Examples
Las montañas están cubiertas de nieve perpetua.
The mountains are covered in perpetual snow.
Él busca el movimiento perpetuo en su invento.
He is looking for perpetual motion in his invention.
El condenado recibió cadena perpetua.
The convict received a life sentence.
Matching Gender and Number
Since this is an adjective ending in -o, you must change it to 'perpetua' for feminine words and add an -s for plural (perpetuos/perpetuas).
Placement for Emphasis
Usually, this word comes after the thing it describes. Putting it before (e.g., 'su perpetuo silencio') makes the sentence sound very poetic or dramatic.
Don't forget the 'a'
Mistake: “La nieve perpetuo.”
Correction: La nieve perpetua. Because 'nieve' is a feminine word, the ending of the adjective must change to match it.
Related Translations
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