A. Underline the verbs in the present tense in the following paragraph.
The crust now has about fifteen large plates and several smaller ones.
They move very slowly - about 2-4 cm every year. This may not seem fast
to us, but geological time is measured in the context of millions of years.
Geologists, going by their own calculations, believe that the speed is
strong enough to open up an ocean 2,000 km wide in about 50 million
years. In fact, the Atlantic Ocean has opened up in this kind of a time
frame. It is thus evident why some of the older rocks, such as coal, are
found to be of the same kind on both sides of the Atlantic Ocean.
contanas
Answers
Explanation:
Illogical Time Sequence
Recognize time sequences in your writing and choose verb tenses that logically reflect that sequence. Sometimes the choice of a verb tense affects your meaning.
Kelsey worked at the library for a year.
As the previous sentence shows, the past tense indicates a completed action. Kelsey no longer works at the library.
Kelsey has worked at the library for a year.
Here, the present perfect tense indicates that a past action is continuing in the present. Kelsey is still working at the library.
Kelsey had worked at the library for a year.
In this sentence, the past perfect tense indicates that something else happened after Kelsey's year at the library. For example, Kelsey had worked at the library for a year when she was asked to take over technology development.
When to use the perfect tense
Learn to use the perfect tenses when they are appropriate to your meaning. Don't limit yourself to the simple past tense when writing about past action. In the following sentences, a perfect tense should have been used to establish a clear time sequence.
The car wash stood where the sandwich shop was. (no)
All the things you told me, I heard before. (no)
In the first sentence, since the sandwich shop was in the location before the car wash—they can't occupy the same space at the same time—past perfect should be used for the second verb.
The car wash stood where the sandwich shop had been.
The logic of the second sentence dictates that heard should be in the past perfect tense. The word before is an obvious clue that the hearing took place before the telling, even though both actions were completed in the past.
All the things you told me, I had heard before.
Faulty if clauses
The past perfect tense should also be used in a subjunctive past tense “ if clause.”
If she had thought of it, she would have called you.
A common error is to use the conditional would have or could have in both clauses. Would have and could have should be used only in the clause that states the consequences.
If I had wanted to, I would have made cookies.
not If I would have wanted to, I would have made cookies.
If we had brought matches, we could have made a bonfire.
not If we would have brought matches, we could have made a bonfire.
Inconsistency in tenses
Another common error is illogically mixing tenses in a sentence or in a piece of writing. Choose the verb tense you want to use in your sentence or in your essay. Then make sure that all verbs are consistent, either by being in the same tense or by reflecting past and future times in relation to your main tense.
Roberto went into the market, walks over to the produce section, and picks through the tomatoes. (inconsistent tenses)
In the preceding sentence there is no logical reason to move from the past tense ( went) to the present tense ( walks, picks). Use the past tense or the present tense—not both. Rewrite the sentence using consistent tenses.
Roberto went into the market, walked over to the produce section, and picked through the tomatoes. (consistent tenses)
Look at the verb tenses in this group of sentences.
This new program will pay its own way. It specified that anyone who wanted to use the service has to pay a fee. People who refused to do so won't receive the benefits. (inconsistent tenses)
Notice that the changes in tense between sentences are not related to a clear time sequence. A rewritten version of this piece shows a more consistent, logical use of tenses.
This new program will pay its own way. It specifies that anyone who wants to use the service has to pay a fee. People who refuse to do so won't receive the benefits. (consistent tenses)
In this version, all verb tenses except the first ( will pay) and last ( won't receive = will not receive) are in the present tense. The future tense is correctly used for the first and last verbs because these verbs indicate future consequences.
Irregular verbs
Even when you understand the correct uses of verb tenses, you can run into trouble with irregular verbs. Irregular verbs form the past tense and past participle in a variety of ways (as shown in Table 1), not by adding -d or -ed as regular verbs do.