Final answer:
The pato uses the verb 'grazna' in Spanish.
Step-by-step explanation:
The animal that uses the verb 'grazna' is the pato, which means duck in English. The verb 'grazna' is conjugated in the third person singular form, so it matches with the subject 'pato'.
Example sentence: El pato grazna en el lago. (The duck quacks in the lake.)
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