I blissfully enjoyed The Name of the Wind by Patrick Rothfuss. However, one of the first style quirks that jumped out at me was Rothfuss’s reliance on the constructions it was and there was (and it is, there were, etc.), as in “It was night again.” Out of the prologue and first twenty-one chapters, seven begin with It was. Rothfuss is a talented writer; he’s capable of chapter beginnings like this: “Chronicler walked. Yesterday he had limped, but today there was no part of his feet that didn’t hurt, so limping did no good.” The It was beginnings stick out like seven sore thumbs.
Let’s look at the following two sentences (which I wrote, not Patrick Rothfuss).
It was a dangerous front porch.
There were many people in the room.
First, a brief survey of their grammar.
In the first sentence, the pronoun it serves as the subject of the sentence, followed by the linking verb was and the predicate, a dangerous front porch.
In the second sentence, the pronoun there (yes, it’s functioning as a pronoun here!) is not the subject; rather, the sentence is inverted and the subject, people, follows the verb were. There is an expletive, which is defined in linguistics as a word that fills a grammatical function but is otherwise meaningless.
If you didn't get the intricacies of that, it's okay. My point is to show that it was and there were are not grammatically parallel in the sentence examples. Thus, the reasons to avoid the two phrases do not have to do with grammar.
Other instances of the two phrases cannot or need not be avoided. It was time to go is the same grammatically as It was a dangerous front porch, but the idiom can’t be expressed any other way. In the phrase there is the car, the word there functions as an adverb rather than a pronoun, and the phrase is simply an inversion of the car is there—nothing wrong with that.
So the grammar is all over the place. You just need to keep your eyes peeled for there was and it was appearing on your paper or screen. When you spot it, pause. Is one of the following style principles being violated?
Use fewer words.
There was and it was force unnecessary pronouns into sentences. When we reorganize the above sentence examples, we can cut the initial pronoun from each.
The front porch was dangerous.
Many people were in the room.
Use active verbs.
There was and it was come with a built-in state-of-being verb. When we unravel these constructions, we can replace to be with an active verb (or two).
The front porch buckled in the middle and creaked dangerously.
Many people filled the room.
On second thought, we can take the latter sentence a step further. Since the vivid verb filled strengthens the subject people, let’s delete the adverb many.
People filled the room.
Nice!
Upon spotting it was or there was in your writing, you may in the end decide to not rewrite it, either for the reasons indicated in my confusing paragraphs on grammar or because the phrase sounds right in context. Edward Bulwer-Lytton infamously got away with it in his 1830 novel Paul Clifford:
It was a dark and stormy night.
Twenty-nine years later, Charles Dickens filled an entire chapter with the offending constructions.
But I’d say he barely got away with it, and only because he was Charles Dickens.