SUMMARY
The analysis of the distribution of enclitic forms cu, ceš, ce ... and heverb hteti shows that they cannot be naturally reduced to each other. Thi.s mean. s that the., verb hteti is not.. an auxiliary verb at all, i. e. it does not take part in compound tenses in S.erbo-Croatian. Accord,ing to their complement.& we have distinguished two verbs hteti - hteti1 and hteti. Hteti is a modal verb, hteti a main verb. Furthermore, we have shown that there is a parallelism between 'complements "da + prezent" and "sentence" which can be best accounted for by a transforma tion (18), which may be called in English Subjugation of Infi nitive. This analysis has enabled us to present the structure of auxiliary and modal verbs by rewrite rules (34). Finally, we have shown that an alternative analysis in which all verbs are conceived as main verbs is quite feasible. In this new analysis our results are preserved in the form of an obligatory filter.