учествују

In a sentence

• Студенти учествују у пројекту за заштиту животне средине.

  The students are participating in the environmental protection project.

  Here, 'учествују' is used as the present tense of the verb meaning 'participate,' indicating an ongoing action of involvement.

• Да ли они често учествују у оваквим активностима?

  Do they often participate in such activities?

  In this sentence, 'учествују' is in the interrogative form, asking about the frequency of participation in the activities.

• Иако су били уморни, ипак су учествовали у расправи.

  Although they were tired, they still participated in the discussion.

  Here, the use of 'учествовали' (past tense form) indicates completion of the participatory action despite the circumstance.