Correcting Mixed Sentences

Sentences are mixed if they have two parts that do not fit together grammatically or logically. A mixed sentence occurs when a subject does not fit the verb, as in the following example.

From all his hard work helped Karl graduate.

In this example, the prepositional phrase From all his hard work functions as the subject of the verb--an unusual construction in English. Here is an effective revision for this example.

All his hard work helped Karl graduate.

Another kind of mixed sentence occurs when the subject of the sentence is repeated with a pronoun, as in the following example.

The robber he reached for a gun.

In this example, the pronoun he unnecessarily repeats the subject The robber. An effective revision appears below.

The robber reached for a gun.

Mixed sentences often occur with is when and is where expressions, as in the following examples.

An examination is when you are tested.
     An examination is where you are tested.

An examination is not a time or place. When should be used only when referring to a time, and where only when referring to a place. Here is an appropriate revision.

An examination is a test of what you know.

Is when and is where expressions are usually acceptable during informal conversations, but they should be avoided in academic writing.

Writers should also avoid using the reason . . . is because statements. Study this example.

The reason he likes geology is because the concepts of time are very broad.

Since because means for the reason that, this construction is redundant. Here is an effective revision.

He likes geology because the concepts of time are very broad.

Similarly, do not use the wordy expression for the reason that when because is adequate. The following sentence is wordy.

He failed geology for the reason that he didn’t study very much.

This sentence is better.

He failed geology because he didn’t study.

Which sentence is correct? The reason I am interested in your report is because I enjoy classical music. I am interested in your report because I enjoy classical music.