Section One Verb Tense Agreement
Verb tense agreement refers to the consistency of verb tenses in a sentence, a paragraph, or even an essay.In other words, if you begin your writing in the present tense, do not shift suddenly to the past tense；if you begin in the past tense, do not shift without reason to the present tense.In the following two sentences, the verb tenses are consistent.
1) When the speaker enters the lecture hall, the audience rise.
2) When the speaker entered the lecture hall, the audience rose.
But the tenses in the sentence below shift illogically:
3) When the speaker enters, the audience rose.
Listed below are two rules to get rid of errors in verb tense agreement.
The first rule: Shift verb tense when time is changed.
4) Fifty years ago, Thanksgiving Day was regarded as the opening day of the season for Christmas shopping；today, the season opens immediately after Halloween.
In sentence 4) , the time is changed from fifty years ago to today , so the past tense wasis shifted to present tense opens.
The second rule: Shift verb tense when the meaning calls for such a change.
5) The Forbidden City (紫禁城) was the home of the Chinese emperors and is famous throughout the world for its architecture and historical relics.
In sentence 5) , the past tense wasis used because there aren't any emperors in today's China；the present tense isis used because the architecture and historical relics in the Forbidden City still exist.
In brief, you must maintain consistency in verb tense while writing.Shifting tenses should be done logically.
Practice 2-1-1
All of the following sentences contain unnecessary tense shifts.Make the verb tenses consistent in each sentence.Answers are provided only for the first two sentences.
1.When I am young I used to go swimming in the lake.But now it is so polluted that almost everything in it has died.
2.Thirty years ago, the typical American family consisted of a husband, a wife, and two or three children.Now, there are many marriages in which couples decided not to have any children.