Compound Words for TOEFL/IELTS/TOEIC/ESL/SAT/GRE/GMAT Preparation

Many people may confuse about how to write a word with two words or when to use a hyphen within words, etc. It's simple.

A compound word is made up of two or more words. Sometimes one word isn't enough to express an idea, name an object, or say what a speaker or writer is trying to express, so people make up compound nouns and adjectives.

Compounds come three ways:

1. Closed: written as one word
2. Open: words written separately
3. Hyphenated: words joined by a hypen (a short line)

Here are some common compound nouns and adjectives:

• Closed Compounds:

Backyard, barefoot, blueberry, bookstore, moonlight, classmate, flashlight, granddaughter, greenhouse, homework, motorcycle, paperback, textbook, touchdown, shoelace, applesauce, etc.

• Open Compounds:

Best seller, seat belt, telephone operator, high school, wheel chair, word processor, chewing gum, box office, calling bell, cough drop, cricket ball, day care, dining room, hand bag, hair coloring, life preserver, shopping complex, washing machine, milk shake, tooth brush, pencil sharpener, store keeper, post office, speed breaker, study hall, etc.

• Hyphenated Compounds:

Baby-sitter, editor-in-chief, great-grandchild, air-conditioned, all-purpose, best-selling, break-in, check-in, drive-in, follow-up, full-length, left-handed, long-distance, play-by-play, tax-free, etc.

These words are usually written with hyphens:

1) All fractions written out in words:

For example,

 One-half, two-thirds, five-eighths, three-fourths, etc.

2) All two-word numbers from twenty-one to ninety-nine written out as words:

For example,

 Twenty-six, fifty-eight, forty-three, ninety-seven, etc.

3) Most compounds that begin with self:

For example,

 Self-satisfaction, self-control, self-esteem, self-employed, self-taught, etc.

4) Some two- or three-word family members:

For example,

 Mother-in-law, father-in-law, brother-in-law, sister-in-law, step-sister, step- brother, great-aunt, great- uncle, etc.

Compound Nouns Plural:

1) To make most one-word and two-word compound nouns plural, just add 's' to the end:

For example,

 Briefcases, girlfriends, covered wagons, launch pads, etc.

2) With hyphenated compound nouns, make the most important word plural:

For example,

 Great-grandsons, brothers-in-law, passers-by, etc.

Actually, there are no strict rules for compound words.

Adjective may be either closed or hyphenated (ex: a standby ticket, a stand-up comedian, front-page news, etc).

Verbs are usually open but are occasionally closed or hyphenated (ex: show off one's skills, start to shadowbox, learn to touch-type, etc).

Nouns are most commonly either closed or open, but can also be hyphenated (ex: appear on the front page, achieve a breakthrough, act like a show-off, etc).