OFFICIAL EXPLANATIONProject SC Butler: Sentence Correction (SC1)
Quote:
In the early 1960s, shortly after lasers were invented, Robert Forward, a physicist and science fiction writer, had suggested that it could be used to push sails in space.
Past events and verb tensesIn this sentence, two events occur in the past.
Lasers were discovered.
Shortly after the discovery, Robert Forward had suggested [?] that lasers could ...
•
had suggested is in "past perfect" tense.
Past perfect is constructed this way:
HAD + PAST PARTICIPLE (verbED)]
Past perfect is used to describe the earlier of two past events.
• whenever you see a sentence with two or more events, at least one of which is in past perfect (had verbED), figure out which event came first.
-- If the event rendered in past perfect tense occurred first, past perfect is probably logical.
-- If past perfect is used to describe the
later event, though, that usage is illogical.
In this sentence, two past events occurred sequentially
→ (1) first, in the early 1960s, lasers were invented
→ (2) then, "shortly after" #1, author R. Forward _______ [had suggested?] that lasers could be used to do XYZ.
Did the event rendered in past perfect occur before the other event?
THE OPTIONSQuote:
A) had suggested that it could be used
•
had suggested is illogical.
→ the verb tense itself describes the earlier of two actions (the past of the past)
→ but Robert Forward suggested XYZ about lasers
after lasers were invented
→
had suggested is thus illogical and ungrammatical
See Notes, below, for information about past perfect and simple past verb tenses.
• in addition, the singular pronoun
it does not agree with its plural antecedent,
lasersELIMINATE A
Quote:
B) had suggested that they can be used
•
had suggested is incorrect for the same reasons as those in (A)
• the present tense verb
can is incorrect
→ first, Mr. Forward was not in the present when he commented on lasers
→ second,
had suggested is in the past. Why is the accompanying modal "can" in the present?
-- The modal
can should also be in past tense:
couldELIMINATE B
Quote:
C) has suggested that they could be used
•
has suggested is a
present tense verb and is incorrect
→
has suggested = present perfect, which connects the past to the present.
No present is involved in this sentence.
See Notes for a description of present perfect.
→ This man's action began in the past
and ended. Right after lasers were invented in the 1960s, Robert Forward
suggested that lasers ...
→ in other words, we are not talking about an action that continues into the present or whose effects reach into the present. Wrong verb tense.
ELIMINATE C
Quote:
D) would suggest that it could be used
•
pick the easier error: singular
it does not agree with its plural antecedent,
lasers• would? In this context, no. The action is not a hypothetical, reported speech, an expression of willingness, or habitual action in the past.
→ On the other hand, sometimes in English literature, an author will say that a person "would" do something in the past in order to stress that doing so was unusual. In this case, Forward's suggestion was ahead of its time.
→ Don't worry about this usage, which is usually a literary device. As far as I recall, is not used on the GMAT.
ELIMINATE D
Quote:
E) suggested that they could be used
• By POE, this option is correct
•
suggested fits with the timeline: right after lasers were invented, Forward suggested XYZ
• plural
they agrees with plural antecedent
lasers•
could be used = past tense of
can be used
KEEP
The answer is E.Notes (Feel free to skip this part if you fully understand past and present perfect.)
• past perfect (options A and B)
→ HAD + verbED
→ describes the
earlier (older) of two
pastevents
→ is sometimes called "the past of the past."
Why? Because past perfect (X) is coupled with another event that is also in the past but later in time (Y).
We "look behind" the later event (Y) to describe what (had) happened earlier (X).
The past perfect verb tense itself signals what we are doing.
__|X|____|Y|___ now
At lunchtime, I realized (Y) that I had forgotten my wallet. (X)• requirements for past perfect
(i) the past perfect event must be used logically to describe the
earlier of two events. See, e.g.,
OG VR SC #300.
From above, my forgetting my wallet occurred earlier than my realization.
And
(ii) almost always, using past perfect requires at least one other simple past tense event or a time marker (to depict the Y event).
In the example,
realized is the simple past tense event.
• when do we
not necessarily need past perfect?
→ when, as in this question, we have a sequence word that tells us in which order the two past events occurred.
... shortly after lasers were invented, Forward suggested that they could ....One final note: GMAC seems to be using sentences that contain a simple past event, a sequence word,
and a past perfect event. See, e.g.,
OG 2020 SC #s 215, 227, and 289.
→ Takeaway: a sequence word does not guarantee that we can use only simple past tense for both events -- but a sequence word or other signal is required to describe two events using simple past.
→ Takeaway: If you see two past events and a
sequence word, even if the past perfect is used correctly,
do not eliminate options that use only simple past.
This post, here, explores the "tricky issue" of when to use part perfect.
Present perfect in Option CPresent perfect in (C):
Robert Forward has suggested.Present perfect:
(1) bridges past and present; the event began in the past and it or its effects continue into the present
Correct:
He has commuted from Boston to NYC since 2010. (2) describes repeated action in an unspecified time between the past and now.
Correct:
He has taken TOEFL a few times.(3) describes an action by a still-living person in which time is irrelevant Correct:
She has written extensively about xenophobia and tribalism.Those situations are not similar to the situation in this sentence. Present perfect sounds ludicrous.
COMMENTSAnki2609 ,
sonee@gmail.com , and
BooRadley , welcome to SC Butler.
As always, I am glad to see everyone—new, veteran, and in between.
Learning is not a spectator sport.
Diversity of thought and presentation is good for those who follow.
Well, I can't bump two or three answers to Best Community Reply.
These explanations range from good to outstanding.
I still expect that you are all reading. (Native speakers, too.)
Save one person, I wonder who will understand when I suggest that you read
To Kill a Mockingbird?
close
15 Aug 2020, 23:05
13%
(01:05)
wrong 
