The study looks at the choice of Estonian partitive case forms in modern Estonian usage by inflectional classes. In particular, the analysis is focused on the inflectional classes containing alternative parallel forms. The material analyzed comes from new media texts available in the text corpora of the University of Tartu. The preference of certain forms is explained according to the theory of natural morphology and the frequency of use. In partitive singular, the preference of using a vowel ending vs the t-ending was investigated. In partitive plural, the use of a vowel ending vs the sid-ending was studied. The si-ending, which is known to occur in student essays and in online communication, was not preferred over the sid-ending in the data analyzed. In another group of partitive plural forms the chances of a vowel ending vs the id-ending were looked at.
The study indicated that in most cases analyzed the form accepted in Standard Estonian was preferred. The most unstable word was hüve ‘good’, which has evolved from a t-ending word to a vowel-ending one. In future, the words vistrik ‘pimple’ and ämblik ‘spider’, which are vowel-ending words, could also be used with a t-ending. Lastly, the word aadress ‘address’, which is a vowel-ending word at present, could some day perhaps also be accepted among t-ending words.