Questions & Answers about Takového zloděje jsme neviděli.
Because zloděje is the direct object of neviděli, so it has to be in the accusative case.
For zloděj (a masculine animate noun), the forms are:
- takový zloděj = nominative singular
- takového zloděje = accusative singular
The word takový has to agree with zloděj in case, number, and gender, so it changes to takového.
So:
It is accusative singular.
In this sentence, zloděje is the thing being seen, so it is the direct object of the verb vidět / nevidět.
Because zloděj is masculine animate, its accusative singular looks like this:
- nominative: zloděj
- accusative: zloděje
That is why you get takového zloděje.