past-perfecttense
Let's say you are writing a past event of a diabetic patient to a doctor.
"The patient had consumed 1 whole canned juice of 'del monte' pineapple 240ml, which the patient usually consumes just a half of the juice. Also, 1 pc. of rice cake HAD EATEN/HAD BEEN EATEN as her late afternoon snack, before the blood sugar check.
As you can see, the patient had had her juice & a snack before the blood sugar test. But should I use had eaten or had been eaten?
This is a tricky question. The native ear will immediately recognize that "had been remained" is not correct. The had should be followed by a past participle. Remained and been are both past participles; you can use one or the other, but not both.
So, either of these could be used to start the sentence:
This issue gets tricky, however, when you switch to the passive voice. In that case, you can use he had been followed by a past participle, as in:
That's a valid formation, and it's listed as the past perfect passive verb form in this table1:
So, the question becomes, why can the verb elected be used in this way, but not the verb remained?
The key is that the sentence with elected is using the passive construction, but the sentence with remained has an active construction. As Dave Sperling says on his ESL website:
Because subjects of passive verbs receive the action, verbs that cannot have objects (intransitive verbs) do not have passive forms.
If you look up the words in a dictionary, you'll see that elect is transitive, and remain is intransitive, which is why had been remained sounds so awkward to the native ear, while had been elected sounds just fine – although many native speakers might have a hard time explaining why.
Now, you can explain it for them: "It's because remained is an intransitive verb, so it cannot be used in the passive voice."
As emrys says, it is the since which is awkward here.
I think what the Guardian author means is that the tipping point was reached not in 2005 or at some specific point since 2005, but in the years since 2005. This would reflect what Murray and King said in the 2012 Nature paper: "In 2005, global production of regular crude oil reached about 72 million barrels per day. From then on, production capacity seems to have hit a ceiling at 75 million barrels per day."
But the past perfect is correct here; the author is referring to what was said a year ago by Murray and King, who were referring to the years between 2005 and 2012. The title of the Murray/King paper at that time was in the present perfect: "Climate policy: Oil's tipping point has passed".
Best Answer
Look at the word order:
In the first sentence the subject is the patient.
In the second the subject is the food, so the second sentence has been cast in the passive voice. The rice cake had been eaten.
The difference between the sentences in not in the tense, they both use the same tense: past perfect.
There is no real need to use the passive for the second sentence, so don't. I'm not sure what a cupsize of rice cake means. It's not clear what "it" refers to in "which is usually half of it".