A number of the words we use today are shaped from prefixes, root words, and suffixes that originally came from many other languages, especially Latin, Greek, Old English, and French. By learning some of these, you can analyze unfamiliar words, break them down into their component parts, and then apply their meanings to help unlock their definitions.

Root words (base words) can add either prefixes or suffixes to create other words. Take, for instance, the root word bene, meaning good. If you add various prefixes (letters that come at the beginning of a word) and suffixes (letters that come at the end of a word) to bene, you can create other words such as benefit, benevolent, benediction, and unbeneficial. Each prefix and suffix has a meaning of its own; so by adding one or the other — or both — to root words, you form new words. You can see the root word bene in each of the new words, and each of the new words still retains a meaning having to do with good, but the prefix or suffix changes or expands on the meaning. (The prefix un-, for instance, means “not.” That gives a whole new meaning — an opposite meaning — to the word unbeneficial.)

In another example, look at the root word chron, which comes from Greek and means time. Adding the prefix syn- (meaning together with) and the suffix -ize (meaning to cause to be) creates the modern word synchronize, which means to set various timepieces at the same time. Use a different suffix, -ology, meaning the study of, and you have chronology, which means the study that deals with time divisions and assigns events to their proper dates.

Interesting, too, is the way ancient word forms have been used to create words in modern times. Two thousand years ago, for instance, no one knew there would be a need for a word that meant sending your voice far away — but that's what the modern word telephone means. It's a combination of tele, meaning distant or far away, and phon, meaning voice or sound.

In Appendix B, you'll find other common root words and some examples of modern English words that incorporate them.

The Last Word on Spelling

Here are some rules for spelling words to which prefixes or suffixes have been added.

• Words that end in -x don't change when a suffix is added to them:

  fax = faxing, hoax = hoaxed, mix = mixer

• Words that end in -c don't change when a suffix is added to them if the letter before the c is a, o, u, or a consonant:

  talc = talcum, maniac = maniacal

• Words that end in -c usually add k when a suffix is added to them if the letter before the c is e or i and the pronunciation of the c is hard:

  picnic = picnickers, colic = colicky, frolic = frolicking

• Words that end in -c usually don't change when a suffix is added to them if the letter before the c is e or i and the pronunciation of the c is soft:

  critic = criticism, clinic = clinician, lyric = lyricist

• Words that end in a single consonant immediately preceded by one or more unstressed vowels usually remain unchanged before any suffix:

  debit = debited, credit = creditor, felon = felony

  Of course, you'll find exceptions, such as:

  program = programmed, format = formatting, crystal = crystallize

• When a prefix is added to form a new word, the root word usually remains unchanged:

  spell = misspell, cast = recast, approve = disapprove

  In some cases, however, the new word is hyphenated. These exceptions include instances when the last letter of the prefix and the first letter of the word it's joining are the same vowel; when the prefix is being added to a proper noun; and when the new word formed by the prefix and the root must be distinguished from another word spelled in the same way but with a different meaning: anti-institutional, mid-March, re-creation (versus recreation).

• When adding a suffix to a word ending in -y, change the y to i when the y is preceded by a consonant:

  carry = carrier, irony = ironic, empty = emptied

  This rule doesn't apply to words with an -ing ending:

  carry = carrying, empty = emptying

  This rule also doesn't apply to words in which the -y is preceded by a vowel:

  delay = delayed, enjoy = enjoyable

• Two or more words that join to form a compound word usually keep the original spelling of each word:

  cufflink, billfold, bookcase, football

• If a word ends in -ie, change the -ie to -y before adding -ing:

  die = dying, lie = lying, tie = tying

• When adding -full to the end of a word, change the ending to -ful:

  armful, grateful, careful