Hey ,
Here is what I think....
You can't tell the diference because when you're infatuated, you're "crazy in love," you've lost your senses. You've lost your mind. Infatuation is a delightful form of madness. It's like a short term mental illness, where you lose your ability to reason.
Here's how to tell the difference between love and infatuation.
Love is real, and if you take good care of it, it will last a lifetime. And love can grow.
Infatuation is unreal. The madness of infatuation creates many unrealities. You perceive your love object as vastly more wonderful than is real. You perceive your feeling of infatuation as though it will last forever.
Once infatuation peaks, it starts disappearing until it's gone. It always goes away.
After infatuation goes away, reality comes back to you. You see that your love object has faults, flaws, and the normal number of human quirks. You can't see that when you're infatuated.
After infatuation disappears and reality returns, any bonds you formed with your partner during your madness will stay with you forever. It's those bonds, the memories and the feelings that make up your bundle of love that might lead to marriage and a committed relationship.
So, love is real, and it lasts.
Infatuation is magical, mystical, very unreal, and it always goes away.
HTH