Some languages have quite complex declination systems so, depending on the position in the sentence, the suffixes of nouns may change. How is this handled by Déjà Vu? That depends on the source and target language combination you are working with:
If you are translating from a source language with a complex declination system to a destination language with a simpler declination system:
You have to store each different entry of the source language corresponding to each translation (as if they are completely different words), even if the translation might be the same for more than one entries. As a result, Déjà Vu will recognise the source entry every time and will translate it without giving you multiple matches.
If you are translating from a source language with a simpler declination system to a destination language with a more complex declination system:
You can highlight the source word in question and press F11 and then add, every time you want to add a different corresponding translation to the word. As a result, every time this word needs to be translated, Déjà Vu will give you multiple matches to choose from.