Learn Polish: Ten ślepy pies musi używać innych zmysłów, bo jego oczy nie widzą. - This blind dog must use other senses because its eyes do not see.

For biological body parts that come in pairs, like eyes, ears, and hands, Polish uses special irregular plural forms inherited from an old grammatical number called the dual. The plural of oko when referring to human or animal eyes is always oczy. Interestingly, the regular neuter plural oka does exist, but it is only used for non-biological things like drops of fat floating on soup or the meshes of a net!

Why is 'other senses' translated as innych zmysłów rather than the basic Nominative inne zmysły?

The verb używać (to use) is one of the common verbs in Polish that always requires its object to take the Genitive case. Since the dog is using multiple senses, we must use the Genitive plural endings for both the adjective (innych) and the masculine noun (zmysłów).

The translation says 'its eyes', but the Polish sentence uses jego (his). Why is that?

Polish doesn't have a direct equivalent to the English 'its' that covers all animals. Instead, you choose the possessive pronoun based on the noun's grammatical gender. Because the word pies (dog) is grammatically masculine, it takes the masculine possessive jego (his), even though English naturally translates this as 'its' for an animal.

Do irregular plural body parts like oczy require any special verb endings?