Question

for nouns indeng in o,ch,x,s,ss,sh,we,add-es at the end of the words

Answer 1

Olá!

We follow this rule when we are changing singular nouns to plural ones or when we are conjugating the verbs in the third person singular.

eg.: Tomato → tomatoes
brush → brushes

pass → passes

box → boxes

Espero ter ajudado!

Answer 2

o - potatoes, tomatoes BUT pianos, radios, photos
ch - benches, churches, inches, watches 
x - boxes, taxes, foxes
s - buses
ss - dresses, addresses, kisses
sh - brushes, ashes, dishes