defining/non-defining clauses with 'which/that' and the role of the comma

[Queueuey]

Let's look at these:

1. An American blockade of the Strait of Hormuz has stripped Beijing of up to 15% of its oil, which the Chinese had been receiving from Iran.
2. The American blockade of the Strait of Hormuz has stripped Beijing of up to 15% of its oil which the Chinese had been receiving from Iran.
3. An American blockade of the Strait of Hormuz has stripped Beijing of up to 15% of the oil which the Chinese had been receiving from Iran.
4. The American blockade of the Strait of Hormuz has stripped Beijing of up to 15% of the oil that the Chinese had been receiving from Iran.
5. The American blockade of the Strait of Hormuz has stripped Beijing of up to 15% of its oil that the Chinese had been receiving from Iran.

I wonder which of the 5 sentences may (and with what probability) be construed to mean that
(A) the Chinese had been receiving all of their oil from Iran
(B) 15% of the total volume of oil the Chinese had been receiving had been coming from Iran

By the way, how does the article before "American" impact the meaning?

 

[jutfrank]

Let's start with the article. You would use The if you think that the reader (this sounds like written English) is aware of the existence of the blockade. By using A, you presume that the reader doesn't know about the blockade's existence, which is hard to imagine in this case.

The second question concerns the quantity of oil. We can tell that by the construction of the noun phrase:

a) 15% of its oil

This means that 15% of China's total oil imports came through the strait. The other 85% comes from other countries.

b) 15% of the oil that the Chinese had been receiving from Iran

This means that China continues to receive 85% of what it used to receive from Iran.

Since you're talking about the Strait of Hormuz, it's clear what you're trying to say because we know the facts of the matter: China was receiving oil from several different countries, and 15% of that oil came from Iran, and 100% of this Iranian oil came through the strait. Given that we know that, and presuming that the writer knows that the reader knows and is thinking about the blockade's existence, we have:

The American blockade of the Strait of Hormuz has stripped Beijing of up to 15% of its oil, which the Chinese had been receiving from Iran.

The relative clause that follows the comma is extra, non-essential information. This is why the comma is important to set the meaning.

 

[Queueuey]

Since you're talking about the Strait of Hormuz, it's clear what you're trying to say because we know the facts of the matter:

What about the other 4 sentences? Do they go contrary to what we know and assume?
What if we didn't know the facts of the matter?

 

[jutfrank]

I suppose you're asking about relative clauses.

Your sentence #2 could make sense in an alternative world. It contains a relative clause as part of a long noun phrase :

15% of the oil that the Chinese had been receiving from Iran

The phrase above means that China was receiving a quantity of oil from Iran, and of that total quantity of Iranian oil, 15% has been lost due to the blockade and the other 85% continues to come through the strait. Obviously, this is wrong.

Sentence #3 uses which instead of that but yields the same interpretation. However, that is the better and more natural word in restrictive relative clauses for most people. #2 and #5 are wrong. #1 has the right relative clause but probably has the wrong article. Look at my sentence in post #2 again.