What is the difference between "had engaged", "had been engaged", and "were engaged" in this context?

Question

Prime Minister Narendra Modi disclosed on Saturday that the registration of over 1 lakh companies which had allegedly engaged in suspicious transactions post demonetisation had been scrapped as he sought to cast the goods and services tax (GST) as his second strike against black money and corruption.

Source: 48 hrs before GST, 1 lakh cos lost registration for post-DeMon `lapses' The Times of India (Mumbai)

Is this sentence construction is correct in above news? Why Past perfect is used here?

"companies which had allegedly engaged in suspicious transactions"

Or it can be

"companies which had allegedly been engaged in suspicious transactions"

Or it can be

"companies which were allegedly engaged in suspicious transactions"

Answer 1

Why [is the p]ast perfect [...] used here?

Because the main verb of the sentence--disclosed--is in the past tense and the (completed) actions described by the verbs engage and scrap occurred before that disclosure. As has been mentioned, the sentence is not written in the clearest manner possible. That said, its verb tenses are correct and bog standard.

To address the other options:

...had allegedly been engaged...

just adds another layer of opacity to the writing and either means (a) exactly the same thing as the terser phrasing or (b) means that some other entity was responsible for engaging these companies in suspicious transactions. Sense (b) doesn't seem supported by the rest of the context, so it's just making poor phrasing worse.

...were allegedly engaged...

similarly can mean (a) exactly the same thing as the past perfect or (b) shift it into the passive. Again, sense (b) doesn't seem supported. The difference between the first sense and the past perfect is that the same action is being described, but without reference to the occurrence of the main verb. It suggests a more distant relationship between the two verbs.

He had asked her to marry him before she moved to Topeka.

places the question solidly before the completed action of her move to Topeka.

He asked her to marry him before she moved to Topeka.

places the question in the past and removes any connection between the time of the two verbs, leaving it unclear whether she did in fact ever actually leave.

Answer 2

You ask:

Why Past perfect is used here?

In the sample of purple journatistic prose which you present, there are a number of possible explanations for the use of the past perfect. However, the most likely is not concerned with grammar: Either the writer wished to impress us with his command of English or he had a short character count and needed to increase it to fill the column.

Not a jot of information is added to the account of Mr Modi's action through the use of the past perfect. The "suspicious transactions" took place after demonetization (Mr Modi's removal of 500- and 1,000-rupee notes from circulation), so we already know when the companies engaged in these practices relative to the Saturday when Mr Modi made his announcement. There is no need to use the past perfect to tell us again.

Your other proposed verb forms are similarly unnecessary. The simple past is all we require here:

"...the registration of over 1 lakh companies which engaged in suspicious transactions post demonetisation had been scrapped..."

^{(Note that I have also deleted allegedly, since it's obvious from the rest of the statement that wrongdoing is alleged.)}

You will find on this site many learned explanations of the past perfect, replete with pictures of eyeballs facing this way and that and graphs demonstrating the relative positions of events on a temporal continuum. In many cases like this one, though, the simple past concisely and accurately expresses the relationship between events. If you are interested, FumbleFingers' Perfect Truism presents the worthwhile principle: "Don't use the Perfect unless you really have to."

Answer 3

Let's start with the past perfect:

"companies which had allegedly engaged in suspicious transactions"

Past perfect compares an action in the past which is completed prior to some other past point in time (which can be specified but also which can be implied). See:

past per·fect /ˈˌpast ˈpərfəkt/ adjective 1. (of a tense) denoting an action completed prior to some past point of time specified or implied, formed in English by had and the past participle, as in he had gone by then. - Google

In this case there is a simple past item, the Prime Minister disclosed on Saturday but, prior to this simple past item, there was an earlier past point or points where the companies had allegedly engaged in suspicious transactions.

Second, let's look at the past perfect progressive/continuous:

"companies which had allegedly been engag[ing] in suspicious transactions"

please note the form changes from engaged to engaging

The PAST PERFECT PROGRESSIVE TENSE indicates a continuous action that was completed at some point in the past; more precisely, something that started in the past and continued up to another action or time in the past (or else had finished just before another event in the past).

The change in meaning between the past perfect tense and the past perfect continuous tense is that, while the past perfect tense indicates that the companies had engaged in suspicious transactions at some points in the more distant past (but may have self-corrected that behavior so it could well be something that happened a few times 5-10 years ago but nothing more recent), the past perfect continuous tense would modify that meaning to indicate the companies had continued to actively engage in a pattern of suspicious transactions up to a point just before or even up to the point of the announcement by the Prime Minister.

Third, let's look at the past progressive/continuous:

"companies which were allegedly engag[ing] in suspicious transactions"

please note the form changes from engaged to engaging

The past continuous describes actions or events in a time before now, which began in the past and is still going on at the time of speaking. Both past continuous and past perfect continuous tenses can be used to talk about actions or situations that were in progress at a certain point of time in the past. While the past continuous merely shows continuity, the past perfect continuous tense also puts an emphasis on the idea of duration. It is mainly used to indicate the duration of a past activity or state.

In this particular case, as in many cases, changing to the past continuous tense would modify the meaning from the past perfect in much the same way that changing to the past perfect continuous tense would modify that meaning. The past continuous tense would modify that meaning to indicate the companies had continued to actively engage in a pattern of suspicious transactions up to the recent announcement by the Prime Minister.

Final notes on grammar

You will notice in a couple of instances above I changed engaged to engaging - it is necessary to use the participle form when using continuous tenses in active voice (passive voice is different). Think about a similar set of sentences:

People who had run in the marathon.
People who had been run[ning] in the marathon.
People who were run[ning] in the marathon.

Maybe using this similar but different sentence will help you understand why engaged needs to change to engaging in the second and third examples.

Edit

Because @ColleenV seems to be struggling mightily with this here is some additional information about understanding Active and Passive Voices in Past Continuous and Past Perfect Tenses. I hope the examples in this link along with the many I've already provided, including in my responses below, will help clarify this for anyone who is still struggling to understand it.

Past Continuous Tense

Active sentences in the past continuous tense have the following structure:

Subject + was/were + -ing form of the verb + object

Passive sentences in the past continuous tense have the following structure:

Object of the active sentence + was/were + being + past participle form of the verb + by + subject of the active sentence