Learn Polish: Ten nieśmiały chłopiec nie rozmawia z nikim.

The word nieśmiały (shy) is an adjective. In Polish, the negative particle nie is written as one word with adjectives. However, nie is always written as a separate word before verbs, which is why we must write nie rozmawia.

Why does the sentence use z nikim (with nobody) instead of a word for anybody? Doesn't that make a double negative?

Yes, it literally translates to 'does not talk with nobody'. Polish requires a double negative. When you have a negated verb like nie rozmawia, negative pronouns like nikt (nobody) must be used instead of positive ones like ktoś (somebody) or ktokolwiek (anybody).

Why is the form nikim used after the preposition z instead of just nikt?

The verb rozmawiać (to talk) takes the preposition z (with), which requires the following noun or pronoun to be in the instrumental case. The instrumental form of the nominative pronoun nikt (nobody) is nikim.

Is the adjective nieśmiały related to any other common Polish words?