Hi, Language Lover,
Is the sentence below grammatical?
'There remains substantial further time, thought and effort required.'
'There remain...' does not sound correct to me in this context.
In my opinion, what does not sound right in the sentence above is the participle "required." Perhaps you are trying to say:
- Substantial further time, thought and effort is / are required.
I think both "is" and "are" are correct in the sentence above depending on whether we think of time, thought and effort as forming part of a whole or as different elements.
With anticipatory "there," it is true that the singular sounds better because of the phenomenon known as "number by proximity":
- There remains substantial further time, thought and effort to be applied.