It is a well-known fact that the process of translation is not a simple replacement of the units of one language by the units of another language. On the contrary, it is a complex process, which includes a number of difficulties needed to be overcome by the translator. One of the methods to help the translator is transformations. In this work the most difficult, in our opinion, kind of transformations is examined - grammatical transformations. We consider them to be most complex because they include additional difficulties. When applying grammatical transformations, the translator should be very cautious and attentive not to break the norms of the target language (TL). Moreover, in the given work grammatical transformations are investigated in oral translation, which complicates to a greater degree the problem which the translator confronts.