幾時加es???

If a word ends in -s, -x, -z, -ch or -sh, add -es to the end.
e.g. dress, fox, fizz, watch, wish
When a word ends in -o, also add -es to the end.
e.g. hero, tomato
Exceptions: studio, piano, kangaroo, zoo, buffalo, cargo, motto, volcano. Just add -s to these words.

o,ch,sh字尾要加es
例子: mangoes, watches, washes