What are the different usages of "conditions avec si"?

"Si" can be used to express a condition in three different ways. Two of them will be referring to something that can no longer be realised or acted upon, whereas one of them will be speaking towards the future and what can still be realised. Therefore, all of them express conditions or hypotheses, but only one of them refers to a realisable one.
Si + présent + futur: S'il pleut, je ne sortirai pas. -->This sentence talks about a condition to an action that might be realized by the person in the future. "If it rains, I won't go out." We're still in the present, talking about a possibility that might alter our actions in the future. Si+imparfait+ conditionnel présent: Si vous étiez patients, vous recevriez votre cadeau. --> This sentence talks about a condition to an action in an hypothetical way, and we understand that it is no longer realisable. --> If you were patient, you would get your present. It reflects upon something that could happen, but didn't because of a condition. The sentence explains how it could happen. There is less certainty and more hypothetical discussion compared to the following usage:Si + plus que parfait + conditionnel passé: Si les parents avaient fait attention, l'enfant n'aurait pas tombé. --> This sentence talks about something that has happened in the past, and explains hypothetically the conditions to how it could not have happened. We cannot act upon changing what happened anymore, we only talk about the hypotheses. --> If the parents had paid attention, the child wouldn't have fallen. There is a significant certainty to the chain of events.