First, there's this issue of agreement. The author seems to insist on the plural form of the verb in the case of a compound subject with multiple objects) in the singular, which definitely contradicts everything I know about it from as early as elementary school.
It ["a couch and a coffee table"] is a compound subject since it has two nouns connected by the word "and," which makes it plural, but it's still a subject; and it's always the subject of a sentence that drives your verb choice, even if the subject isn't at the beginning of the sentence.
Now that you know the subject is "a couch and a coffee table" and that it's plural, it's easy to choose the right verb: "are." Plural subject take plural verbs. (The subjects are underlined in the following examples.)
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A couch and a coffee table are in the room.
There are a couch and a coffee table in the room.
Page 2.
Did you see what I did with the last two sentences? In the first one, I used the common sentence order and put the subject first:
A couch and a coffee table are in the room.
In the second one, I flipped it around and added a "there are" to make an expletive sentence:
There are a couch and a coffee table in the room.
The way I was taught about the subject-verb agreement with expletive there is/are is that the choice of is or are depends on the number of the first following noun:How to Determine Subject-Verb Agreement in an Expletive Sentence
If you decide to keep a sentence with a "there is" or "there are" at the beginning, the trick to choosing your verb to use is to find the real subject of the sentence.
There IS a couch and a few chairs in the room V. There ARE a few chairs and a couch in the room.
Unless we're talking about two different things here, of course. And I am totally not getting what she's talking about.
The other beef of mine with the author's recommendation to avoid expletives as 'bad taste/poor style' can definitely be explained by the fact that the blog is an excerpt from her better-writing manual:
Mignon Fogarty is Grammar Girl and the founder of Quick and Dirty Tips.
Check out her New York Times best-seller, “Grammar Girl’s Quick and Dirty Tips for Better Writing.”
Many sources say that expletive sentences are bad style and should be avoided, but I think that advice is extreme, especially in fiction.
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Nevertheless, you can often rewrite expletive sentences to make them more straightforward, and you can see from our earlier example how easy it is to get rid of the word "there" and rephrase the sentence.
"There are a couch and a coffee table in the room" easily becomes "A couch and a coffee table are in the room." If you want to go wild, you could even use a more descriptive verb and write, "A couch and a coffee table sit in the room," or "A couch and a coffee table grace the room."
When you're editing your work and find a sentence that starts with "there are" or "there is," it's worth spending an extra second to check whether rewording it would make your writing better. Often it does.