My father is 72 he is good in health but now he can not talk properly. if not a stroke, what can cause this?

Uncertain: Your father needs to see a physician right away. Being unable to talk properly often is a sign of a stroke, but it can be caused by other serious medical problems as well, including a brain hemorrhage, neurological damage to the oral cavity/tongue, or other metabolic diseases that can affect the ability to talk. Take your father to a doctor right away for evaluation and treatment.

Too vague: A more detailed explanation of how he is not "talking properly" is needed to make a proper diagnosis. I suggest seeing a neurologist.

Get checked: May have other problem such as a mass.