Ineffective coordination

Coordinate structures are appropriate only when you intend to draw the reader’s attention equally to two or more ideas:

Example sentence: Professor Sakellarios praises loudly, and she criticizes softly.

If one idea is more important than another—or if a coordinating conjunction does not clearly signal the relation between the ideas—you should subordinate the lesser idea.

Example sentence with editing. Original sentence: Four hours went by, and a rescue truck finally arrived, but by that time the injured swimmer had been evacuated in a helicopter. Revised sentence: After four hours, a rescue truck finally arrived, but by that time the injured swimmer had been evacuated in a helicopter.

Three independent clauses were excessive. The least important idea has become a prepositional phrase.

Exercises:

Identifying coordination

Identifying subordination

Identifying sentence emphasis 1

Identifying sentence emphasis 2

Combining choppy sentences

Using coordination and subordination 1

Using coordination and subordination 2

Using coordination and subordination 3