Construction of the Roman Colosseum, which was officially known as the Flavian Amphitheater, began in A.D. 69, during the reign of Vespasian, was completed a decade later, during the reign of Titus, who opened the Colosseum with a one-hundred-day cycle of religious pageants, gladiatorial games, and spectacles.
(This question is from Official Guide. Therefore, because of copyrights, the complete question cannot be copied here. The question can be accessed at GMAT Club)
The sentence says that the construction of the Roman Colosseum began in A.D. 69 when Vespasian ruled. The sentence also provides additional information about Roman Colosseum – this colosseum was official known as the Flavian Amphitheater.
As we read the sentence further, we come across “was completed a decade later”. Logically, we understand that this verb phrase (verb followed by other details) belongs to the subject ‘Construction’. However, we have already come across one verb (began), so we can see that these two verbs are not joined properly. (As is, they are joined by a comma; they need to be joined by ‘and’).
The sentence then provides more information about Titus using a relative clause. I believe it is enough to understand that there is additional info about Titus; we don’t need to worry about the details.
The sentence, therefore, has one error.
(A) Incorrect. For the error described above.
(B) Incorrect. Even though “officially known as …” changes this information to present tense from the past tense given in the original sentence, I wouldn’t recommend that you reject an option statement for this reason. Such slight modifications in meaning are allowed on GMAT.
The reason this option is incorrect is that it uses “begun”, which is the past participle form of “begin”. Without an auxiliary verb (has, have, had), it doesn’t function as a verb; it functions as a verb-ed modifier. So, the error is that an incorrect verb form has been used.
(C) Correct. The original error has been corrected by introducing ‘and’. No new errors have been introduced.
(D) Incorrect. Please note that ‘begun’ is used as a verb-ed modifier in this option. That is why it has been joined by ‘and’ with another verb-ed modifier ‘known’. This option has two errors:
- “known” and “begun” constitute a list, but they are not logically parallel. “known” modifies ‘Roman Colosseum’ while “begun” modifies ‘Construction’. Since they are modifying different entities in the sentence, they are not logically parallel and thus should not be part of a list.
- There is no verb for ‘Construction’. The verb ‘was completed’ now belongs to ‘it’, which has been added in this option.
(E) Incorrect. There is no verb before ‘and’ for the subject ‘Construction’. The verb ‘was begun’ belongs to the relative pronoun ‘which’.