Bunuel
As no one knows the truth
as fully as him, no one but him can provide the testimony.
A. as fully as his, no one but him
B. as fully as he, no one but him
C. as fully as he does, not one but he
D. as fully as he does, no one but he alone
E. as fully as he does, no one but him
Okay this one reminds me of something similar I had seen in the past, and I didn't get it right back then so let me explain to help out folks on this one. Here my take:
Concept 1: Here we have a parallelism marker via the comparison used "as fully as" so both side have to be parallel, so:
no one knows.....
he knows. or
he does know Concept 2: Ellipsis of the verb, where we can repeat the Verb if no marker and if marker the form is plural. The verb form used should be present in the comparison made i.e.
we need 'knows' to ellipse 'knows' over and 'know' to ellipse 'know' over, we cannot swap out.Concept 3: But used as a preposition, remember But as preposition is used as an alternative to except (for), apart from or to introduce the only thing or person that the main part of the sentence does not include. But can also be used as a conjunction to contrast 2 clauses or actions, where the much-covered parallelism kicks in.
Point no. 131 in
Wren and Martin ‘when but is preposition, take care to use accusative or objective form.’
Ex-Conjunction: She worked late, but she did not finish all of her work.
Ex- Preposition: Nobody but (except) him was present. It means he was the only person present. OR Nobody will help you but me (not :I) OR Nobody but him was present
As
no one knows the truth
as fully as him, no one but him can provide the testimony
A. as fully
as his, no one but him
<subjective pronoun form needed for parallelism>
B. as fully as he, no one but him [Not intuitive but correct]C. as fully as he does, not one
but he <Concept 3>D. as fully as he does,
no one but he
alone <Redundant alone>E. as fully as he does
(we need know but have knows only) ,
no one but him <Concept 2>Takeaways: Objective form follows prepositions, Prepositional use v/s conjunctional use and Ellipsis.The first time it may take some time to get used to the above, but once you add it to your knowledge base, you'll get faster at spotting these nuances.
Hope this helps