Some anthropologists regard the early hominids' manner of

(B) as less efficient than it is in
(C) as less efficient than that of

1. isn't the word 'efficient' important part of comaprison since it is attached to 'LESS'
Why not we have 'efficient' on both sides of comparison


2. in B] and C] -'' IT or THAT OF ''refer back to hominid's manner of walking and not just the word 'manner'. Isn't there an ambiguity?

Hello Anshul1223333,

We hope this finds you well.

To answer your query, "efficient" is not repeated because the entire phrase "less efficient" is the comparison marker.

For example, consider this sentence - "Today the weather is less sunny than it was yesterday." - here, the grammatical elements being compared are the clauses "Today the weather is" and "it was yesterday", and "less sunny" is the comparison marker.

Further, the pronoun "that" can be used to refer to just the main noun of a noun phrase - "manner of walking" in this case - so, there is no ambiguity.

We hope this helps.
All the best!
Experts' Global Team

In general, the two parallel parts in a comparison will contain all of the DIFFERENCES between the two items/ideas that the sentence is trying to compare.

A well-written sentence avoids unnecessary repetition. If some aspect is exactly the same on both sides of a comparison, then, that part is not written twice unless it MUST be (for grammatical reasons and/or to resolve ambiguity).


In THIS sentence, though, "efficient" is not part of the parallel items at all—it's part of the COMPARISON STRUCTURE:
X is less efficient than Y

This structure is functionally identical to simpler examples such as "X is smaller than Y". If you understand why "smaller" is not part of 'X' or 'Y', then, by analogy, you also understand why "less efficient" is not part of either of the two parallel structures above.




No ambiguity.

The pronouns "it" and "they" ALWAYS refer to a noun WITH ALL OF THE ORIGINAL CONTEXT AND ATTACHED DESCRIPTIONS.
So, "it" in choice B is WRONG, for the exact reason you wrote here: it stands for the entire phrase "the early hominids' manner of walking". With that referent, the right-hand side becomes complete nonsense (there's no such thing as EARLY hominids' gait in MODERN humans!)
It's not ambiguous—it's unambiguously INCORRECT.

On the other hand, the pronouns "that" and "those"—which appear in comparison sentences—specifically DON'T carry forward all of the original context attached to the noun. (This is how comparisons work in general: The two items are similar enough to be parallel, but they MUST somehow differ. You can't write a comparison between something and itself!)
These pronouns ONLY EXIST because they are UNLIKE "it" and "them".
In this context, "that" stands for "manner of walking"—the sentence compares early hominids' manner of walking to modern humans' manner of walking.

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