djelovati

Djelovati is a verb in Croatian, Bosnian, and Serbian that means to act, to operate, to function, or to have an effect. It is used for people who take action, for machines or systems that operate, and for substances or circumstances that produce a consequence or influence.

The usage covers several related senses. For human agency, it describes how someone acts or behaves: “On djeluje kao svjedok.” For machinery or processes, it describes functioning: “Stroj djeluje pravilno.” For pharmacological or biological effects, it denotes action on a target: “Lijek djeluje na organizam.” It can also indicate influence on events or conditions: “Politika djeluje na gospodarstvo.” Often it appears with the preposition na to indicate the target of the action, or with protiv to indicate opposition, as in "djelovati protiv zagađenja." A common formulation is djelovati na temelju dokaza, meaning to act on the basis of evidence.

Djelovati is imperfective, with standard present tense forms: ja djelujem, ti djeluješ, on/ona/ono djeluje, mi djelujemo, vi djelujete, oni djeluju. Past tense forms reflect gender and number: djelovao (masc), djelovala (fem), djelovalo (neut), e.g., “djelovao sam.” Future is formed periphrastically or with the основу of the infinitive, e.g., “djelovat ću” or “djelovat ćemo.”

Related terms include djelovanje (the action, operation, or effect) and djelotvoren/djelotvoran (effective; with noun forms such as djelotvornost meaning effectiveness). The word is widely used in everyday language, journalism, science, and public discourse to describe the act of acting or the functioning of something.