Conjunctions balance one thing against another, either in similarity or in contrast. By knowing a conjunction’s function, you form easily understood relationships between words, phrases, and clauses.
- Balance Similarities, Contrast Differences.
The most common conjunction, and, should join items to show similarity or something in common. Bread and butter live a balanced life together, physically, logically, and grammatically. “Bread and the yellowish solid produced from churning cream” balance physically but not grammatically. “Bread and laughter” balance grammatically but not physically or logically.
- Danny worked on the farm in the summer, and but his studies were the top priority during the school year. (For contrast, but is needed instead of and. The active verb worked doesn’t balance with the passive were. Two sentences would be better.)
- Should I go home or try to make it to work?
- We talked and laughed but and had a good time. (Since talked and laughed coincide with a good time, a participial phrase is better: We talked and laughed, having a good time.)
- Show Correlation.
The correlative conjunctions give relative importance to two sentence elements. The most common pairs are both—and, either—or, neither—nor, whether—or, and not only—but also.
- You should bring either a vegetable or a dessert to the potluck dinner. (The second article balances the either—or condition.)
- John couldn’t decide whether to get up early or to sleep late. (The second preposition to balance the whether—or condition.)
- Both young and old Everybody will love reading my book. (Beyond the spectrum of young and old, who’s left?)
- Both an An offensive lineman and a defensive back scored a touchdown. (Both indicates a collective effort. Since an offensive and a defensive player can’t make a play together, use of both is meaningless if not misleading.)
- The tornado devastated not only the church but also the business next door three miles away. (Without a need for contrast, “but also” has no meaning. You might say, The tornado devastated the church and the business next door.)
- Weigh In on the Differences
A subordinating conjunction modifies the weight of the main clause.
- Before she learned to drive, Susie dreamed of becoming being a race car driver. (He dream was more than becoming a driver. She wanted to be one.)
- Since Because he had no volunteers, he had to do all the work himself. (Since is better used relevant to time, not cause and effect.)
- John had to reboot his computer when after the power went out. (Amazing technology, a computer that reboots without power.)