Adjectives and Adverbs
To tell apart adjectives and adverbs, "the adverb questions" are a handy tool. Asking the right ones helps you identify the adverbs in a sentence.
|Sam freed up the clog with a plunger.
||How did Sam free up the clog?
||With a plunger.
|Max barely studies.
||To what extent does Max study?
|Last week, Alex visited China.
||When did Alex visit China?
|Jordan, come here with your assignment.
|Ezra became a doctor to help people.
||Why did Ezra become a doctor?
||To help people.
You were right: hundreds of years ago is usually an adverb of time. However, here it is not one. An illustration:
|The Vietnam War ended over 30 years ago.¹
||When did the Vietnam War end?
||Thirty years ago.
|Gabriel thought back to the three items he'd discovered in her jewelry box: the compass, a soul and the tarnished ring he gave her hundreds of years ago.²
||When did he give her the ring?
||Hundreds of years ago.
|Colonization hundreds of years ago is held accountable for such situation.
||What kind of colonisation? is the sensible question here.
||None (unless we change the sentence to Hundreds of years ago, colonisation was responsible for such a situation and alter its meaning).
Now it is fair to assume hundreds of years ago is filling the adjectival position. That brings us to the second half under this header: adjectives.
Usage under the next heading implies
N * of years ago is rarely used as a noun unit. Far more common is
N from * of years ago:
¹ collected from here
² collected from here
N * of years ago
Here is some usage of this form where
* of years ago is strictly an adjective.
Everything we've checked out so far says that supernovae billions of years ago look very similar to the ones of today.¹
— Exploding stars tell all by Robert Irion in Astronomy: November 1998
It enabled me to look back to the remote past, into the material records of man's efforts hundreds of years ago, and contrast them with the modern progress of arts and sciences.
— Engineer: An Autobiography by James Nasmyth
However, compared to its use with
* of years ago as an adverb, the other usage is rare in COHA. For example,
John Quincy Adams thirty years ago declared that ....
— New Departure of the Republican Party by Henry Wilson in Atlantic Monthly: January 1871
¹ Note this is also correct should look have been a transcribing error for looked; however, then billions of years ago is likely an adverb.
The improvable parts are three in number.
Colonization hundreds of years ago
Some noteworthy points here:
- If this colonisation has been referenced before, use "the colonisation".
- According to the first heading, "Colonisation from hundreds of years ago" is a better choice. It will be understood easily by many people.
By contrast, "Colonisation hundreds of years ago" is still understandable though rarer. One might consider it for more formal documents.
Is held accountable
Some thoughts on the passive voice used here:
- Who holds colonisation accountable? goes unanswered. One should not use the passive voice to avoid taking responsibility for a claim. Besides, the active voice is more clear.
One should (a) mention the party (Let us call it Responsible Party), as in "Responsible Party holds Colonisation responsible ..." or (b) cite an authoritative source where this claim is justified, as in "Dogs can relieve stress.¹"
The key problem here:
- Here, you use "situation" as an abstract noun. However, you really mean to use the countable situation. This calls for using "such a situation".
The following form, which uses Responsible Party as a pseudonym, is one candidate.
Responsible Party holds colonization from hundreds of years ago accountable for such a situation.
Another alternative in case you wish to be subtler:
Colonization from hundreds of years ago is held accountable for such a situation.¹
(where "¹" points to a footnote)
You could combine the footnote and the active voice for what I think is the best variant.