"Vidíš toho osla?"

Translation: Do you see that donkey?

[AquaRoseDr]

What's up with toho?

[VladaFu]

accusative case

[ian672582]

Why "osla" and not "osel" ?

[BoneheadBass]

Osel is the nominative case, which is used for the subject of the sentence. Here we need the accusative case, osla, since it is the direct object of the verb. Compare, for example:

-- Ten osel je velký. / That donkey is big. (Subject)
-- Vidím velkého osla. / I see a big donkey. (Object)