Breakdown of Он идёт из книжного магазина.
он
he / it (for a masculine noun) / it (for a neuter noun)
магазин
store, shop
идти
to go (on foot) / to proceed, go (of a process)
книжный
book (adj), bookish
Questions & Answers about Он идёт из книжного магазина.
Why do both книжного and магазина have special endings here?
They are in the genitive case because of the preposition из (from). In Russian, whenever you talk about movement out of or from a place using из, the location and any words describing it must be in the genitive case.
Why is the ending of книжного spelled with a "г" but pronounced with a "v" sound?
The dictionary form of this adjective is книжный. Because магазин is a masculine noun in the genitive case, the adjective takes the genitive masculine ending -ого. A strict rule in Russian is that the -его and -ого endings for adjectives and pronouns are always pronounced as if they were written with a "v" (-ево and -ово).
Why use the adjective книжного instead of just the noun for book (книга)?
In English, we often put two nouns together to make a new concept (like "book" + "store"). In Russian, you usually have to turn the first noun into an adjective. So instead of a "book store", Russians say a "bookish store" (книжный магазин).
Why does the sentence use идёт instead of another verb for going, like ходит?