Can somebody explain to me the time frame of this sentence.
Archeological sites in the remote locations are not likely to have been previously identified.
I also tried to simplify it
Archeological sites are unlikely to have been previously identified.
What is confusing me is that both are and have been are used in the sentence. It looks like a mixture of active and passive. Please explain.
Archeological sites are unlikely to be found.
This seems quite understandable.
In the first sentence the article is unnecessary.
Archeological sites in remote locations are not likely to have been previously identified.
These first two examples convey the meaning that it is unlikely as of now that archeological sites have already been found in the past, hence the use of both "are" and "have been". Your third example insinuates more that archeological sites are unlikely to be found in the future.
As for active and passive, I'm a native speaker so my knowledge of exact grammatical rules isn't perfect, but it seems to me that the sentences are in passive voice only and the use of both verbs doesn't contradict this. Someone with superior grammar knowledge may disagree, or if I'm correct have a more satisfying and succinct explanation.
