Most nouns ending in _o_ add _es_ to form the plural; as, _heroes, negroes, potatoes, stuccoes, manifestoes, mosquitoes._ Words ending in _io_ or _yo_ add _s;_ as, _folios, nuncios, olios, ratios, embryos_.
The following words, being less frequently used, often puzzle us to know whether to add _s_ or _es_ to form the plural: _armadillos, cantos, cuckoos, halos, juntos, octavos, provisos, salvos, solos, twos, tyros, virtuosos._
Many nouns that end in _s_ have a plural appearance, and we are often perplexed to know whether to use _this_ or _these,_ and whether to employ a singular or a plural verb when the noun is used as a substantive.
_Amends_ is singular. _Assets, dregs, eaves, bees, pincers, riches, scissors, sheers, tongs, vitals,_ are plural. When we say _a_ _pair of pincers,_ or _scissors_, or _shears,_ or _tongs,_ the verb should be singular. _Tidings,_ in Shakespeare’s time, was used indiscriminately with a singular or plural verb, but is now generally regarded as plural.
_Alms_ and _headquarters_ are usually made plural, but are occasionally found with a singular verb. _Pains_ is usually singular. _Means, odds,_ and _species_ are singular or plural, according to the meaning.
“By _this means_ he accomplished his purpose.” “What other _means is _left to us?” “Your _means are_ very slender, and your waste is great.”
These are usually pluralized by adding _s_; as, _the Stuarts, the Caesars, the Beechers, the Brownings._
Shall we say _the Miss Browns, the Misses Brown,_ or _the Misses Browns?_ Great diversity of opinion prevails. Gould Brown says: “The name and not the title is varied to form the plural; as, _the Miss Howards, the two Mr. Clarks.”_
Alexander Bain, LL. D., says: “We may say _the Misses Brown,_ or _the Miss Browns,_ or even _the Misses Browns.”_
The chief objection to the last two forms is found when the proper name ends with _s_, as when we say, _the Miss Brookses, the Miss Joneses, the Miss Pottses, the_ _Miss Blisses._ The form _the Misses Brooks_ is objected to by some on the ground that it sounds affected. On the whole the rule given by Gould Brown is the best, and is quite generally observed.
Both words are made plural, _Knights Templars,_ a very unusual way of forming the plural.