The line of descent of apes and humans is believed by palaeontologists

B. "to be split": indicates that the splitting occurs in the present (in general - eqv. simple present)...wrong

E. "to have split": indicates that the splitting has already occured (in the past - eqv. present perfect).... right

The following examples might further clarify:

He is believed to go there. = it is believed that he (generally) goes there. (in the present)
He is believed to have gone there = It is believed that he has gone there. (at some point in the past)

Similarly,
The line is believed to be split = It is believed that the line is (generally) split.(in the present)
The line is believed to have split = It is believed that the line has split (at some point in the past)

Confused between option B and E
How to choose between believe to be and to have

sayantanc2k

I don't see anything wrong with A either. Afterall it is a fact and there is no harm in presenting it in simple present form. Please guide.

azhrhasan

The Split happened in the past and it is still there so "Has", whereas the simple present is used for eternally true events

I hope this clears ur doubt

This is ultimate explanation for this question.

1. When you see options given, it’s a contest between “that” vs “to”. In this case you might want to see whether main verb is passive or active voice.
2. “Is believed by” is passive voice. Here you need to know following rule.
3. “Subject(noun) + passive voice verb + to do/to have p.p” | “It + passive voice verb + that-clause”
4. The given sentence satisfies “Subject(noun) + passive voice verb + to do/to have p.p” rule.
5. “~ years ago”, at the end of the sentence, provides that two events (Paleontologists believe and the line splits) occurred in different time line. And we can infer that splitter of the line happened way ahead.
6. Therefore, “to have split” is correct.

Hope it helps

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How is have here the correct usage for "the line" (which is singular) ?
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I don't understand your question. Can you specify the question please?

Hello expert, I think the most important is not tense, but active/passive voice. The line can’t do the action (split into), so I think we should use passive voice——>the line is to be split into. Mind to elaborate further? Much thanks.

Hi Mavisdu1017,

In general, it is not the case that the active voice necessarily implies that the subject is performing some concrete action. Some verbs, called stative verbs, simply indicate state -- e.g., verbs related to perceptions and the like. As an example, in the sentence "John likes apples", there is no "action" action that is being performed by John, even though the sentence uses the active voice. Grammar and meaning may not always correspond to the same idea in all constructions.

In this particular sentence, using the passive variation would make it sound as if someone/something came and split this particular line, which is obviously not the case. Hence the active voice construction is correct.

Hope this helps.

Isn't "have" used for indicating a time period that started in the past and continues in the present/has some relevance in the present. But in this question, the line split 5 million years ago, so how can "have" Be in the correct answer.

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