Shifts in sentence construction refer to an improper change in structure somewhere in a sentence which results in inconsistency. Some shifts are deliberate, but unintentional shifts can cause confusion. It’s sometimes difficult to identify these shifts. The most common shifts relate to shifts in verb tense, shifts in person or number, and shifts in voice.
Shift in Verb Tense
Shifts in verb tense are created when a sentence moves between past, present or future tense. This is especially common in narrative essays, but can also occur in academic essays, which should use present tense. Sometimes, the verbs in a sentence may refer to action that is occurring at different times, which would require different tenses. Otherwise, maintain consistent tense, unless the intended meaning requires change.
Ex.
During the soccer game, Brett’s dad stood up and screams at the coach.
In this example, the first verb, “stood,” is past tense. The following verb, “screams,” is present tense. If he stood up (past tense) he must scream in the same tense, which would be “screamed.”
Ex.
The teacher explains that the papers were due Friday, but the students complained about the due date.
The teacher “explains” in present tense, so the students should complain in present tense.
Ex.
During the baseball game, the sky darkened, the wind blew up, and a rumbling boom announces the impending storm.
The time frame is introduced as past tense: “darkened” and “blew up” are both past, so “announces” should be the past as well.
ESL Hint: Don’t be fooled by the introductory words, “During the game.” Even though “during” means an action is continuous in general, it does not mean that the sentence action is necessarily continuous.
Shift in Person or Number
Is the subject of the sentence the person speaking (first person), the person spoken to (second person) or the person spoken about (third person)? Shifts in person mean mixing these “persons” within a sentence. Students often use second person “you” in academic writing when first or third person is preferred.
First Person = I, we
Second Person = You, your
Third Person = he, she, it, one, they
Ex.
If one lifts weights consistently, you’ll gain muscle mass and reduce body fat.
One may get chicken pox if you do not get vaccinated.
This is one of the most common tense shifts in academic papers. “One” is third person; “you” is second person.
Ex.
If someone must put dissect the frog, they should do it while closely supervised.
In the above example, “someone” is third person, singular; “They” is third person, plural. To repair, change either.
If someone must dissect the frog, he or she should do it while closely supervised.
Or
If the class must dissect the frog, they should do it while closely supervised.
Ex.
Clerks get paid less than assistants, though a clerk does the same type of work.
This is an error in number. “Clerks” is plural, and “a clerk” is singular. Choose one or the other.
A clerk gets paid less than an assistant, though a clerk does the same type of work.
Clerks get paid less than assistants, though they do the same type of work.
Shift in Voice
Shifts in voice refer to mixing active with passive voice. A sentence beginning in active voice should remain in active voice. If the subject acts on something, it’s active. If the subject is acted upon, it’s passive. However, sometimes a shift in voice is justified, though be careful it’s communicated clearly.
Ex.
The visiting team won the tournament, and a trophy was awarded to them.
In this example, “team won” is active voice; “trophy was awarded” is passive. To correct, turn the passive second part of the sentence to active:
The visiting team won the tournament, and they were awarded a trophy.
Ex.
The thieves approached the woman, and she was asked for her purse.
This example can be corrected in the same way as the previous:
The thieves approached the woman, and they asked her for her purse.
As you can see, it’s not always easy to locate shifts in tense, person, or voice. We often know something isn’t quite right, but you have a hard time figuring out what exactly it is.
CORRECTION: We often know something isn’t quite right, but WE have a hard time figuring it out!
I told you so!
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