But at the same time there are several exceptions form this rule.
Plural of roof and hoof.
When at school i was taught that the plural of roof is rooves and the plural of hoof is hooves.
This is exactly how hooves is obtained as the first plural of the noun.
And this is how you get hoofs.
It wasn t until the last 40 50 years that hooves began to pick up steam.
But hooves woke up in the 20th century and by about 1970 it overtook hoofs in usage and that s where it has stayed.
For example roof chef and others these do not apply the previous rule but simply add the s normally at the end of the word after f in order to obtain the plural form.
I was taught rooves in grade school on the east coast.
Hoofs is also a plural form of hoof the horny part of an animal s foot.
Dwarf dwarves elf elves hoof hooves roof rooves.
The plural of hof is hofas which when pronounced would have sounded like hooves.
Just like roof hoof also started with two plural forms hoofs and hooves.
Poof and poofs follow the same rule.
English pluralization can be complicated.
On the other hand spoof simply adds the plural s suffix to become spoofs.
Should it become rooves like hooves.
For a good 250 years hoofs was the primary plural form of hoof analogized with the word roof which has roofs as a plural form.
Not all nouns follow simple rules when transitioning from single to plural form.
And just like roof hoofs was the dominant one.
Maybe my teachers were wrong.
Hoof comes from the old english word hof.
Hoofs is a much older rendering of the plural form of hoof.
Hoof for instance becomes hooves in the plural.