“My” inside the noun

Hebrew can attach a person-ending directly to a noun to show possession. The base word סֵפֶר, “book,” appears here with the first-person ending ־ִי, giving סִפְרִי, “my book.” Notice that the base vowels also change. The ending carries the person relationship, but the entire surface form must be learned as a Hebrew word, not assembled mechanically from unchanged dictionary pieces.