An explanation of how the modern directory enquiries system works

Hi, In the following sentence, should I use "explanation" or "explanations"? Sentence1: I needed to tailor explanation(s) to each student. Sentence2: I commented on whether the explanations … Her explanation is not clear, i am keen to kow more in details. And the second situation is you have found a good explanation for your query and think that what she gave explanation was not … Hola a tod@s, hace poco me explicaron que la palabra "explanation" puede ir acompañada de, entre otras, las preposiciones "on" o "of". El contexto en el que estaba la palabra era … Hello! I'm writing explanations for some problems. I searched these problems on the internet and found wonderful explanations. In my notes regarding a problem I want to give credit for … Explain to him how Brazil could have lost to Holland means the explanation should be in his direction. In (b) explain me, there is no preposition "to" indicating the direction of the explanation. …

[Grammar] - Which is correct? Explanation why vs explanation as to …