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    #1

    tense shift

    Hi Teachers,

    "Further analysis on the specific sorbents is needed to determine how to best build artificial trees, and a method of storing the carbon after it has been collected must also be analyzed." ( A literature review of CO 2 capture directly from ambient air, Joshua Fabian, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering.)

    Why does the 2nd independent clause ("a method of storing the carbon after it has been collected must also be analyzed.") shift the tense from a present perfect to a present tense?

    Can I say "a method of storing the carbon after it is collected must also be analyzed." or "a method of storing the carbon after it has been collected must also have been analyzed." ? Do they have the same meaning?

    and Is "Futher" an adverb modifying "to determine" ?

    Thank you

  1. Raymott's Avatar
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    #2

    Re: tense shift

    Quote Originally Posted by iboon14 View Post
    Hi Teachers,

    "Further analysis on the specific sorbents is needed to determine how to best build artificial trees, and a method of storing the carbon after it has been collected must also be analyzed." ( A literature review of CO 2 capture directly from ambient air, Joshua Fabian, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering.)

    Why does the 2nd independent clause ("a method of storing the carbon after it has been collected must also be analyzed.") shift the tense from a present perfect to a present tense?

    Can I say "a method of storing the carbon after it is collected must also be analyzed." Yes.
    or "a method of storing the carbon after it has been collected must also have been analyzed." ? No
    Do they have the same meaning? The two clauses immediately above do not mean the same thing.
    and Is "Futher" an adverb modifying "to determine" ? No, it's an adjective qualifying 'analysis'. As an adverb, it would followed by a comma. ("Further comments are below" - adjective. "Further, comments are below" - adverb.")

    Thank you
    To me it seems to use the passive voice of the present tense in both clauses.
    "Is needed" is not present perfect; that would be "has needed". "Must be analyzed" is also present tense, passive.
    "Has been collected" is also passive, but in this case, it's present perfect, but the main clause is "a method of storing the carbon [...] must also be analyzed." They could have written "after it is collected", but their choice is legitimate.

    While it's true that a method of storing carbon "must be analysed" (according to the writers), there's no event mentioned before which such storage "must have been analysed".

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    #3

    Re: tense shift

    Quote Originally Posted by Raymott View Post
    To me it seems to use the passive voice of the present tense in both clauses.
    "Is needed" is not present perfect; that would be "has needed". "Must be analyzed" is also present tense, passive.
    "Has been collected" is also passive, but in this case, it's present perfect, but the main clause is "a method of storing the carbon [...] must also be analyzed." They could have written "after it is collected", but their choice is legitimate.

    While it's true that a method of storing carbon "must be analysed" (according to the writers), there's no event mentioned before which such storage "must have been analysed".
    Thank you Raymott,

    I don't understand on your last comment "there's no event mentioned before which such storage "must have been analysed".". Could you give me an example of sentence if the writer did mention; what should the sentence look like, please ?

    Cheers,

  2. Raymott's Avatar
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    #4

    Re: tense shift

    Quote Originally Posted by iboon14 View Post
    Thank you Raymott,

    I don't understand on your last comment "there's no event mentioned before which such storage "must have been analysed".". Could you give me an example of sentence if the writer did mention; what should the sentence look like, please ?

    Cheers,
    "Of course, before the carbon can actually be accepted, the storage must have been analysed and approved."
    It's true that "it must be analysed and approved", but the above sentence stresses not simply that it must be done, but that "it must have been done" before certain events can occur (such as accepting the carbon).

    Compare:
    Client: If we are to proceed further, the storage must be analysed.
    Company: Certainly, that will be done. So, we have an agreement?
    Client: I'm sorry, I meant that the storage must have been analysed already before we can move forward.

    Some people might call this a matter of style, but if you want the difference, that's it. You could achieve the same effect with adverbs.
    Last edited by Raymott; 02-Mar-2014 at 08:29.

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