Questions & Answers about Мама показывает мальчику новую игрушку.
Why do both мальчику and игрушку end in -у in this sentence?
They actually have that ending for different reasons! Мальчику (to the boy) is the indirect object—the person receiving the action. This means it is in the Dative case, which adds -у to masculine nouns like мальчик. On the other hand, игрушку (the toy) is the direct object—the thing being shown. It is in the Accusative case, where feminine nouns ending in -а (игрушка) change to -у.
Does Russian need a word for "to" in front of мальчику?
No extra word is needed here. By changing the noun to the Dative case (мальчику), you are already expressing the idea of "to the boy" or "for the boy".
Why is the adjective for "new" spelled новую?
Adjectives must match the gender, number, and case of the noun they describe. Since игрушку is a feminine noun in the Accusative case, the dictionary form of the adjective (новая) must change to its feminine Accusative form, which is новую.
Can I change the word order to Мама показывает новую игрушку мальчику?