I know we live in a world of short cuts and abbreviations, especially in our communications.

The apostrophe often takes a back seat; many young people never use it at all. This diminutive bit of punctuation can make one’s writing more clear, especially in possessives. The apostrophe can definitely clarify ownership if it is used correctly. There are some acceptable variations; however, you will never be wrong if you follow three simple rules.

First, if your noun is singular, its possessive will always be on target if you add an apostrophe and an s: girl = girl’s; town = town’s; Jess = Jess’s; Mr. Jones = Mr. Jones’s. Some people favor adding only an apostrophe to a singular noun ending in s, but if you follow the rule, you can’t be wrong.

If a plural noun does not end in an s, you must make it possessive by adding an apostrophe and an s: women’s; children’s.

The third rule holds that a plural noun that does end in s needs only the apostrophe (added to the end): animals’; shoes’; the Harrises’.

To form possessives of plurals, it helps to spell the plural noun correctly first. Rules for plurals are not quite as simple as for possessives, but there are some commonly used forms one can remember.

Many nouns form their plural by simply adding an s.

If a noun ends in s, ch, sh, x, or z, its plural is formed by adding es: rashes, crutches, buses, boxes and buzzes are all correct plurals.

When a noun ends in a y preceded by a consonant, the plural is formed by changing the y to i and adding es: duties, parties, entries. If the noun ends in y preceded by a vowel, the plural is formed by adding s: trays, monkeys, envoys.

The plural of a noun ending in an o preceded by a vowel is formed by adding s: studios, ratios, duos. For most nouns that end in o preceded by a consonant, its plural just adds an s: autos, solos, pianos.

There are always exceptions to rules, and this allows for such words as tomatoes, potatoes, echoes and heroes.

Most nouns ending in f or ff add an s: roofs, dwarfs, staffs. Plurals of some nouns ending in f or fe change this ending to ve and add s: calves, loaves, wharves. Careful listening can sometimes help you in spelling these correctly. If in doubt, though, look up the singular in the dictionary (or your computer). Irregular plurals will be provided there.

Some other irregular plurals are: crises, hypotheses, geese. And some are the same whether singular or plural: corps, Swiss, sheep, deer.

Compound words without a hyphen form their plurals at the end of the word: armfuls, teaspoonfuls, cupfuls. If there is a hyphen, including a noun and its modifiers, the plural is added to the noun: mothers-in-law, attorneys-general, passers-by.

Finally, names are made plural with either s or es: the Stacks, the Amoses, the Lyonses.

First step: recall a few rules. Second step (if in doubt): LOOK IT UP.

— Sandi Ekberg taught high school English in Medford for 30 years. If you have grammar questions, email her at ifixgrammar@charter.net.