What should the ves ending be added to form a plural nouns

There are other words ending in f or fe that change their plurals to ves:

calf - calves

half - halves

knife - knives

leaf - leaves

loaf - loaves

life - lives

wife - wives

shelf - shelves

thief - thieves

yourself - yourselves

themselves Words ending in ff you just add s to make the plural.

cliff - cliffs

toff - toffs

scuff - scuffs

sniff - sniffs

Some words ending in f add s:

roof - roofs

chief - chiefs

Some words can have both endings ves or s:

scarf - scarfs/scarves

dwarf - dwarfs/dwarves

wharf - wharfs/wharves

handkerchief - handkerchiefs/handkerchieves