Three words often confused are the homonyms there, their, and they’re.
Their is a possessive adjective. It always precedes a noun and indicates possession:
Is that collie their dog?
That cabin is their country residence.
They’re is a contraction of the words “they are”:
They’re interested in buying your house.
Do you know if they’re at home?
There has more than one function. It is used as an adverb of place:
See that Victorian house? I lived there when I was nine.
I think I left my keys in the kitchen. Please look to see if they are there.
There is used as a sentence opener:
There is a tide in the affairs of men,/Which, taken at the flood…
Yes, Virginia, there is a Santa Claus.
Note: Beginning a sentence with there is sometimes the correct stylistic choice, but a common error is to begin a sentence with there when beginning with a subject would be better. For example:
Weak: There will be a brass band to meet the war hero at the airport.
Better: A brass band will meet the war hero at the airport.Weak: There are plenty of reasons for her to refuse his advice.
Better: She has plenty of reasons to refuse his advice.
As an author with an English teacher for a mother, I was taught at a young age not to used their as a subject as you never begin a sentence with a adjective. There describes where the item is. It is: The book is over there. It is not Over there is the book, there the book is. While expressing a complete thought, both expressions use to many words to make a single statement.
This house is their primary residence.
Their original residence is in Chicago.
In the first example, this house is where they most often reside.
The second simply states that while the family’s original home is in Chicago, it is not their primary residence.
They’re going to a movie
They are going to the movie.
In my opinion it is always preferable to use proper grammar than to lazily use contractions. I have never liked contraction. Contractions are just a more acceptable form of slang.
I do not read that author; emphasis the fact that the individual has read one of the author’s books, but h/’she is not likely to read another book written by that that particular author.
I don’t like that author; is not emphatic.
There is a problem with this sentence. Vs. This sentence has a problem.
The second sentence is shorter, has no unnecessary words, and emphasizes the real subject, the sentence. In the original sentence, ‘there” is a placeholder.