Indirect object nouns and pronouns (i pronomi indiretti) answer the question to whom? or for whom? In English, the word "to" is sometimes omitted:

We gave a cookbook to Uncle John.

We gave Uncle John a cookbook.

In Italian, the preposition a is always used before an indirect object noun:

Ho regalato un libro di cucina allo zio Giovanni. (I gave a cookbook to Uncle John.)

Perché non regali un profumo alla mamma? (Why don