Learn Croatian: Djeca se igraju u plićaku. - The children are playing in the shallows.

The word djeca is a collective noun. Even though it declines like a feminine singular noun and takes feminine singular adjectives, it always takes a plural verb when acting as the subject.

Why do we use the reflexive word se here instead of just saying igraju?

When you mean play in the sense of children playing around or having fun, you must use the reflexive verb igrati se. The non-reflexive igrati is used when playing a specific sport or game, like igrati tenis (to play tennis).

The noun plićak ends in -k. Why doesn't the -k change to -c in the locative case here?

The preposition u indicating location requires the locative case. For masculine nouns, the locative singular ending is -u, giving us u plićaku. The k-to-c sound change only triggers before the vowel -i, which you would see in the nominative plural form plićaci.

How does the noun plićak relate to other Croatian words for shallow?

It is directly built from the adjective plitak (shallow). By adding a suffix, it becomes a masculine noun specifically meaning a shallow area of water, like a shoal or the shallows at the beach.