SC: has / has been

stop@800 · Posted: Fri Oct 10, 2008 9:23 am Post subject: SC: has / has been

In astronomy the term “red shift” denotes the extent to which light from a distant galaxy has been shifted toward the red, or long-wave, end of the light spectrum by the rapid motion of the galaxy away from the Earth.

1. to which light from a distant galaxy has been shifted
2. to which light from a distant galaxy has shifted
3. that light from a distant galaxy has been shifted
4. of light from a distant galaxy shifting
5. of the shift of light from a distant galaxy

Confused between A and B.
Please help

gmat009 · Posted: Fri Oct 10, 2008 9:33 am Post subject:

B is better than A.

What's OA

schumi_gmat · Posted: Fri Oct 10, 2008 10:50 am Post subject:

IMO A.

The passive voice is used. Hence Has been is appropriate.

vivek.kapoor83 · Posted: Fri Oct 10, 2008 11:39 am Post subject:

imo a.........light is being acted upon by RAPID MOTION... so passive

Bidisha800 · Posted: Fri Oct 10, 2008 9:19 pm Post subject:

rotten old 9 year old og question.

codesnooker · Posted: Sat Oct 11, 2008 4:49 am Post subject:

codesnooker · Posted: Sat Oct 11, 2008 5:14 am Post subject: Re: SC: has / has been

kris610 · Posted: Sat Oct 11, 2008 6:45 am Post subject:

I go with B. Note the '..by the rapid motion..' in the second part of the question indicating the shift is a result of this. So 'has been shifted....by' seems the correct idiom.

stop@800 · Posted: Sat Oct 11, 2008 8:13 am Post subject:

OA A

I accept the point that since the construction is passive so I need to use has been shifted...

Thanks a lot !!

kris610 · Posted: Sat Oct 11, 2008 9:12 am Post subject:

Stacey Koprince · Posted: Tue Oct 14, 2008 11:30 am Post subject:

I received a PM asking me to comment on usage of have/has vs. have been/has been here.

In this case, I'm guessing that the question is really about the distinction been has shifted and has been shifted.

Both of these are present perfect, which is constructed by using "have" or "has" plus the past participle (regular form ends in -ed). "Has BEEN shifted" is also passive because "been" is a form of the verb "to be."

So the question here is: should this sentence be active or passive? As a general rule, we prefer active to passive, BUT when we're dealing with some things set in stone (that is, the non-underlined stuff), we have to look at the whole sentence set-up to see if it dictates active or passive.

So, strip it down:
Light (has shifted / has been shifted) toward X by Y.

Or even more simply:
Light (has shifted / has been shifted) by Y.

Is the light shifting itself? Or is the light being shifted by something else? If the former, use active. If the latter, use passive. In this case, it's the latter, so we need the passive "has been shifted." A is the right answer.

When you're deciding between active and passive, the inclusion of the preposition "by" often indicates a passive sentence. The noun following the "by" is the thing that's actually performing the action indicated by the verb. And if the noun performing the action is within a prepositional phrase, then that noun is not the subject... so the subject is not performing the verb (action). If that's the case, the subject is having that action performed on it... and that dictates passive structure.

You can also try what I did above: ask yourself whether the subject (light) is performing the action (shifting itself) or whether the subject (light) is having the action performed on it (being shifted by something else). This can help clarify whether you need active or passive.