RT Journal Article SR Electronic A1 StehlĂ­k, Petr T1 JF Romanica Olomucensia YR 2013 VO 25 IS 2 SP 151 OP 159 DO 10.5507/ro.2013.018 UL https://romanica.upol.cz/artkey/rom-201302-0006.php AB This article examines three aspects closely related to the mechanisms of interfixation and parasynthesis in Spanish: 1) the importance of diachronic approach for analyzing parasynthetic and interfixed formations; 2) the semantic value of the affix in question; and 3) the consequences of the interpretation of the final segment as derivative or inflectional morpheme in parasynthetic and interfixed verbs. According to our research, the concepts of interfixation and parasynthesis are both based on a diachronic perspective, which makes difficult the application of purely synchronous methods to analyze words formed by these processes. Another problem in common is that in both procedures, it is difficult to determine the specific semantic value of the affix (interfix or prefix). As for the third above-mentioned aspect, the interpretation of the verbal suffix (especially -ar) as inflectional morpheme necessarily leads to the redefinition of all parasynthetic and interfixed verbs, turning these into suffixed or prefixed words, respectively.