Depends on the prayer. Foolish people in this world ask for material things. Every so often it gets granted. There you have an answer
Spiritual people don’t ask for material things. They ask for progress in meditation. They only want God. So how do you know God heard that prayer. **You know that prayer was answered when material things are taken away from you. Initially there is tremendous hardship until every fiber in your being says – no more. I will not come back every again. Nothing except God matters. Hold on to it. In time you will get an awakening. A tug of war ensues. You will get your wishes granted and you will crave the worldly desires. You fall. Once again you go through a dry spell. Until one fine day Satan or Maya cannot tempt you. Then you will progress super fast. **
Lastly there are those great individual you can no longer fall. How do they pray? They don’t. They merely have a thought. It instantly materializes. They never want anything in this world. But they may occasionally say I wonder what Krishna looked like. Krishna appears in person. Or Jesus
Isn’t that wonderful?
Bhavin