What this suffix does
The suffix -age creates nouns that name a collective action, a process, a quantity or a result. From "dam" you get "damage"; from "pack" you get "package"; from "marry" you get "marriage".
Many -age words are borrowings from Old French, so the pronunciation can surprise: -age does not sound like /eɪdʒ/ (the word "age") but like /ɪdʒ/ = "ij". package = PAK-ij, marriage = MA-rij.
Two main groups
1. High-frequency everyday words: damage, package, marriage, village, manage, language, advantage, message, passage, storage.
2. Technical and business words: percentage, coverage, shortage, usage, voltage.
The first group is essential A2-B1 vocabulary.
-age = -aje: many cognates
The -age suffix has Old French origins and produces -aje in Spanish. Cognates are common:
message = mensaje
passage = pasaje
voltage = voltaje
percentage = porcentaje
However not all work the same: "marriage" = matrimonio (not "marriaje"), "damage" = daño (not "damaje"). The -aje pattern works better for technical and formal words.