Formal:
* गाय की दो आँखें होती हैं। (Gaay ki do aankhen hoti hain.) - This is the most grammatically correct and formal way to say it, literally translating to "A cow has two eyes."
* गाय में दो आँखें हैं। (Gaay mein do aankhen hain.) - This is another formal option, translating to "There are two eyes in a cow."
Informal:
* गाय के दो आँखें हैं। (Gaay ke do aankhen hain.) - This is a more informal version, using the possessive marker "ke" instead of "ki."
Note:
* The word for "cow" in Hindi is गाय (gaay).
* The word for "eye" in Hindi is आँख (aankh).
* The plural of "eye" is आँखें (aankhen).
You can choose the option that best suits the context and your level of formality.