In the thesis I investigate the ways in which Serbian and Croatian linguistic usages and norms have changed or been changed since the break-up of Yugoslavia in the early 1990s. I focus on changes, which are believed to have been induced by contact with English. By looking into different linguistic domains such as lexis, word-formation and grammar, I conclude that the largest differences in the prescribed norms and the language usages, in terms of linguistic innovations, are present in the vocabulary. In addition,I make evident that the less visible the innovations are the morelikely they are to be similar (if not identical)in the Croatian and Serbian language communities. The reasons behindthese differences, especially in vocabulary, are found within the domain of language policy and language planning where the prevailing political tendenciesand with them the glottopolitical tendencies before and after the break-up of Yugoslavia led to the abolishment of Serbo-Croatian and the introduction of Croatian, Serbian, Bosnian and later Montenegrin as official languages.