Most nouns ending in ‘O’ form their plural by adding an ‘s.’
Musical nouns such as solo s. Nouns of Spanish and Italian origin such as casino s. Abbreviated nouns, e.g. disco s
However, there are exceptions to this rule! The more common of these words are emboldened below:
buffaloes, calicoes, cargoes, desperadoes, dingoes, dominoes, echoes, embargoes heroes, innuendoes, jingoes, mangoes, mosquitoes, negroes, noes, peccadilloes, potatoes, stuccoes, tomatoes, tornadoes, torpedoes, vetoes, volcanoes.
Some words can end with ‘o’ or ‘oes’
For example: eskimos, flamingoes, halos, mementos, stilletoes and zeroes!
Some words have no singular form:
alms, binoculars, measles, news, pants, pliers, riches, spectacles and trousers.
Some words have the same singular and plural form:
aircraft, cod, deer, grouse, salmon, swine and trout.
Some plurals differ greatly: