The verbs ending in -avati, -ovati, -evati and -ivati belong to frequently used or iterative verbs, and we define them as imperfect verbs that express repeated actions. These verbs do not belong to the same category and do not have the same present tense endings, so native speakers often make mistakes while using them. In the theoretical part, the emphasis is placed on the distribution of different types of verbs, as well as on the formation and the use of their present tense forms. The practical part of the thesis is based on the survey in which 179 respondents participated. The respondents were divided into categories according to their level of education, the dialectal variations and the reflection of jat in their communicative acts. They were asked to fill out a questionnaire consisting of three tasks, each containing ten sentences. The results were analysed and categorised according to the above-mentioned criteria. The research aimed to determine whether the respondents could recognise the correct present tense form of the verbs, or whether they could produce the present tense form of the verbs offered in the infinitive forms. The objective was to point out the most common deviations and possible reasons behind these deviations. The results showed that the respondents were most successful dealing with the first task, i.e. in the sentences in which they had to choose the correct answer (two verbs were offered). They were less successful in the second task, in which they had to form the present tense forms of the verbs offered in the infinitive forms. They were least successful in the third task, in which they had to decide whether the verbs in the sentences were used correctly or incorrectly. The research results showed that neither the level of education nor the dialectal variation with the accompanying reflection of jat probably has a significant influence on the recognition of the correct present tense forms of the verbs and that the speakers have mastered the norms of the Croatian standard language. Future research should investigate whether the frequency of the verb use affects the accuracy of recognizing or producing the present tense forms of the given verbs.