Use of "S" and "Of" in English

Hello, candidates due to growing competitions nowadays English is like maths so the things in English should be logical. Here we are going to see proper use of "s" and 'of' in case of possession.

Rule1- Apostrophe is used with the following ways to express possession

Living things

Mohan's book, A cow's horn, A woman's purse

Rule2- If a plural noun ends in s/ es, s is not added while using an apostrophe

Boys' hostel, Girls' school, working women's hostel

Rule3- when a noun ends in a hissing sound, 's' is not added after the apostrophe

For peace' sake, for conscience' sake, Ganesh idol

Rule4- don't try to use an apostrophe with non-living things in particular like

chair's leg instead of this use leg of the chair

At least one mark is fixed in English section from this small idea so don't forget to like share and best wishes to all of you.

Thanks.