Sentence Correction

The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.

A. that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding
B. that the universe had begun in an explosive instant 10 to 20 billion years ago and had been expanding
C. that the beginning of the universe was an explosive instant 10 to 20 billion years ago that has expanded
D. the beginning of the universe to have been an explosive instant 10 to 20 billion years ago that is expanding
E. the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding


Can anyone help in answering this question? I do apologize the underline is from the word THAT to EXPANDING.

Many thanks.

IMO A

Answer is A.

Has been expanding states that it started expanding and is expanding now also.

began word states that this instance happened in the past.

expalnation for A is that Both verbs in the second clause
correctly take universe as their subject.

Can you please explain what that means and also what parts are parallel here i mean verb began is parallel with what .Also is expanding a modifier modifying universe

How about (E), have begun shows the event is still relevant today. But there is a "TO" before the verb "have begun" thats bothering...can someone throw light on this.

aspirant1 wrote:How about (E), have begun shows the event is still relevant today. But there is a "TO" before the verb "have begun" thats bothering...can someone throw light on this.

i think the biggest problem with have is that its plural and the universe( subj) is singular

Usage of Present perfect tense:

Present perfect = Have/has + past participle.

If a event has taken place in the "past" and still continues to be true in the present then use Present perfect tense.

Here in this sentence:

Universe: subject
began: past tense.
has been expanding : present perfect tense.

SO A does the job.

@ aspirant 1:
E can't be the right option as " for the event that took place need to represented in "past tense" .A does that clearly.

navdeepbajwa:

I dont think " parallelism " plays any role here.This sentence deal with verb tense.

@gmatmachoman,

As per MGMAt Sentence Correction Guide,one has to look for parallelism if you see "and" in a sentence. In that case,"has been expanding" should be parallel to a part of the sentence before "and", which is not the case here.


Please help me if i am missing anyhing.

DERBY29 wrote:The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.

A. that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding
B. that the universe had begun in an explosive instant 10 to 20 billion years ago and had been expanding
C. that the beginning of the universe was an explosive instant 10 to 20 billion years ago that has expanded
D. the beginning of the universe to have been an explosive instant 10 to 20 billion years ago that is expanding
E. the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding


Can anyone help in answering this question? I do apologize the underline is from the word THAT to EXPANDING.

Many thanks.

clearly the answer must be A
because the first sentence uses " ago" and the second part uses "since" thus its tenses must be past simple and present progressive perfect tense

DERBY29 wrote:The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.

Many thanks.

The word "perfect" is a fancy grammatical term for "past".

has + verb (for a singular subject) and have + verb (for a plural subject) = present perfect = present past

The present perfect tense is used to describe the present in terms of a past action.

For example, one use of the present perfect tense is to describe an action that started in the past and might continue in the present:

Since the beginning of the year, John has memorized 100 GMAT idioms.

The word since indicates that John started to memorize GMAT idioms sometime after the beginning of the year (in the past) and that he might still be memorizing GMAT idioms now, in the present.

In answer choice A, the word since requires that the verb has been expanding be in the present perfect tense because the universe started to expand after the explosive instant of the big bang (in the past), and it might still be expanding now, in the present.

The verb began is in the past tense because the universe began 10 to 20 billion years ago, in the past.

When you're trying to sort out a tense issue, always look for time indicators such as since and 10 to 20 billions years ago. Such indicators can help you to determine the correct tense.

Hope this helps!

one action in past and the second action is going on in that case use simple past in first action and present perfect in the second action.

GMATGuruNY wrote:

DERBY29 wrote:The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.

Many thanks.

The word "perfect" is a fancy grammatical term for "past".

has + verb (for a singular subject) and have + verb (for a plural subject) = present perfect = present past

The present perfect tense is used to describe the present in terms of a past action.

For example, one use of the present perfect tense is to describe an action that started in the past and might continue in the present:

Since the beginning of the year, John has memorized 100 GMAT idioms.

The word since indicates that John started to memorize GMAT idioms sometime after the beginning of the year (in the past) and that he might still be memorizing GMAT idioms now, in the present.

In answer choice A, the word since requires that the verb has been expanding be in the present perfect tense because the universe started to expand after the explosive instant of the big bang (in the past), and it might still be expanding now, in the present.

The verb began is in the past tense because the universe began 10 to 20 billion years ago, in the past.

When you're trying to sort out a tense issue, always look for time indicators such as since and 10 to 20 billions years ago. Such indicators can help you to determine the correct tense.

Hope this helps!

I don't understand, why "has expanded" is incorrect and "has been expanding" is correct. As far as I know, these two forms are both Present Perfect:

has expanded --> present perfect simple
has been expanding --> present perfect continuous

Can somebody explain, why the present perfect simple is incorrect here?

thx a lot!

GMATGuruNY wrote:

DERBY29 wrote:The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.

Many thanks.

The word "perfect" is a fancy grammatical term for "past".

has + verb (for a singular subject) and have + verb (for a plural subject) = present perfect = present past

The present perfect tense is used to describe the present in terms of a past action.

For example, one use of the present perfect tense is to describe an action that started in the past and might continue in the present:

Since the beginning of the year, John has memorized 100 GMAT idioms.

The word since indicates that John started to memorize GMAT idioms sometime after the beginning of the year (in the past) and that he might still be memorizing GMAT idioms now, in the present.

In answer choice A, the word since requires that the verb has been expanding be in the present perfect tense because the universe started to expand after the explosive instant of the big bang (in the past), and it might still be expanding now, in the present.

The verb began is in the past tense because the universe began 10 to 20 billion years ago, in the past.

When you're trying to sort out a tense issue, always look for time indicators such as since and 10 to 20 billions years ago. Such indicators can help you to determine the correct tense.

Hope this helps!

Hi Guru,

Please comment on the statements below. Do they make sense?

The widely accepted big-bang theory holds that all the planets in the solar system began in an explosive instant 10 to 20 billion years ago and have been expanding ever since.

The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and had been expanding for several billion years.

TIA,
GK

Should the right wording be --> 'The widely accepted big-bang theory holds THAT the universe began in an explosive instant 10 to 20 billion years ago and THAT IT has been expanding' for parallelism sake and in terms of general GMAT preference ? @GMATGuruNY

Hello Everyone!

Let's take an in-depth look at this question to determine how to best get to the right answer! First, here's the original question with any major differences between each option highlighted in orange:

The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.

(A) that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding
(B) that the universe had begun in an explosive instant 10 to 20 billion years ago and had been expanding
(C) that the beginning of the universe was an explosive instant 10 to 20 billion years ago that has expanded
(D) the beginning of the universe to have been an explosive instant 10 to 20 billion years ago that is expanding
(E) the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding

After a quick glance over the options, a couple major differences jump out:

1. How they begin (the universe began / the beginning of the universe was)
2. How they end (has been expanding / had been expanding / has expanded / is expanding)

Since verb tenses tend to be easier problems for test takers to spot, let's start with #2 on our list. The writer is trying to convey that the Big Bang started in the past, and the universe started to expand then and is still expanding today. That means we need to find options that use present perfect progressive tense! Let's see which options best convey this meaning with the correct verbs:

(A) that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding --> present perfect progressive = OK

(B) that the universe had begun in an explosive instant 10 to 20 billion years ago and had been expanding --> past perfect progressive = WRONG
(This suggests that the expansion stopped at some point in the past, which isn't true.)

(C) that the beginning of the universe was an explosive instant 10 to 20 billion years ago that has expanded --> past perfect = WRONG
(This suggests the expansion happened before some other past event, which doesn't make sense.)

(D) the beginning of the universe to have been an explosive instant 10 to 20 billion years ago that is expanding --> present tense = WRONG
(This doesn't properly show that the expansion started in the past - it just happens in the present, which isn't right.)

(E) the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding --> present perfect progressive = OK

We can eliminate options B, C, and D because they don't use the correct verb tense to convey the intended meaning clearly.

Now that we're left with only options A & E, let's take a closer look to figure out which is the better choice:

(A) that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding

This is CORRECT! It uses the clearest and most accurate verb tenses to convey meaning. It uses past tense to say that the Big Bang "began" in the past, and it "has been expanding" ever since.

(E) the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding

This option is INCORRECT because it uses the past perfect "have begun" instead of just using plain past tense to show that the Big Bang happened in the past. There is no other past event in the sentence that happened and ended later, so there's no need for past perfect tense.

There you go - option A was the correct choice all along!


Don't study for the GMAT. Train for it.