
Plural and possesive - really not that confusing, pic: http://www.susancorso.com
The s at the end of the word is a source of confusion to many – native and non-native speakers but it is relatively simple once one understands the underlying principle.
An extra “s” at the end of a word generally indicates plural: cat – cats, car – cars, concept – concepts
There is an exception for nouns ending on s, z, ch, sh and x – to make it easier to pronounce those plural forms they take an -es plural form
beach – beaches, fox – foxes, fish – fishes
Then there are the possessive forms which indicates that someone owns something (it is like the genitive):
“This is Mike, Jane’s new boy-friend.” (Mike “belongs” to Jane)
“The family’s house has five bedrooms” (the house belongs to the family)”
If the noun already ends on an s, z, or x the possessive s is generally dropped “Charles’ new bike”, “Max’ ambition is to become president”
Lastly, the possessive plural – use the plural form and add the apostrophe: “the singers’ voices are simply beautiful”
There are irregular plural forms of everything, as to be expected – but this covers the vast majority of cases.