Can Past Perfect Continuous tense be used to say that something continued beyond the specified event if we don't even use the duration?

Question

Reference: In the book 'Advanced Grammar in Use by Martin Hewings' on page no. 14 it is written that 'The past perfect continuous can be used to talk about a situation or activity that went on before a particular past time and (i) finished at that time, (ii) continued beyond it, or (iii) finished shortly before it:'

(i) We’d been driving for about an hour when the engine suddenly stopped.
(ii) She felt terrible during the interview because she had been suffering from fl u since the previous day.
(iii) When I last saw Omar, he’d been running and was out of breath.

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Example:"I’d been finishing some work in the garden when Lea arrived, so I didn’t hear her come in."
in this example, the author didn't use the duration (since/for/before, etc), but the context tells us that the action of finishing the work continued beyond the event of Lea's arrival.

My question: Can Past Perfect Continuous tense be used to say that something continued beyond the specified event if we don't even use the duration (since/for/before, etc)?

The documentary crew had been filming the reef when a sea turtle finally appeared.
In this example, would it be correct if I want to say that he had started filming before the turtle appearance and continued after that? or do I need to say that 'for three days' (duration)?

Answer of Chat GPT: 'Yes, in both of your examples, the past perfect continuous tense is used to convey that an action was ongoing before a specific past event and continued beyond it. Even without explicitly mentioning the duration (using "since," "for," etc.), the context makes it clear that the actions had a continuous nature.

In the first example: "I’d been finishing some work in the garden when Lea arrived, so I didn’t hear her come in." The use of past perfect continuous ("had been finishing") suggests that the action of finishing the work in the garden was ongoing before Lea's arrival and likely continued afterward.

In the second example: "The documentary crew had been filming the reef when a sea turtle finally appeared." Here, the past perfect continuous tense ("had been filming") indicates that the filming was in progress before the sea turtle appeared and likely continued afterward. The context implies that the crew started filming before the turtle's appearance and that the filming activity extended beyond that specific event.

So, in both cases, you can use the past perfect continuous tense without explicitly stating the duration, and the context will convey the idea that the action continued beyond the specified event.'

Answer 1

Example: I’d been finishing some work in the garden when Lea arrived, so I didn’t hear her come in.

in this example, the author didn't use the duration (since/for/before, etc), but the context tells us that the action of finishing the work continued beyond the event of Lea's arrival.

I had been finishing some work means something like "I was in the final stages of working on something". Semantically that clause boils down to "I was doing something". The full sentence could be paraphrased:

I was doing something, so I didn't hear Lea come in.

Casting "I was doing something" in the past perfect continuous, when the subordinate clause is introduced by when, merely creates a muddle. It clarifies nothing at all about the temporal relationship of the "doing something" to Lea's coming in, and actually is much less clear in its meaning than the past continuous:

I was doing something, so I didn't hear Lea come in.

Answer 2

Yes, Chat GPT is correct. You can say that someone had been engaged in some activity (for a specified or an unspecified time) when something happened.

Answer 3

Answer of Chat GPT: 'Yes, in both of your examples, the past perfect continuous tense is used to convey that an action was ongoing before a specific past event and continued beyond it. [BUZZER]

The documentary crew had been filming the reef when a sea turtle finally appeared.[okay]

The past perfect continuous requires a previous action, usually in the simple past but does not require mentioning a duration with for or since etc.

In this sentence:

"I’d been finishing some work in the garden when Lea arrived, so I didn’t hear her come in." [okay]

We are only told what you had been doing, not that it continued after she arrived. We have no idea what "you" did after that. We simply have no idea of that. This is similar to: I was working when she arrived. It tells us nothing about after that.

The point of the PPC is an ongoing action up to a specific moment in the past with something else occurred.

I had been reading a magazine//when he arrived.