A lot of English speakers have trouble distinguishing between the homonyms their, they’re, and there. Although they sound the same they have entirely different meanings. They’re putting all their bets on the horse over there. In other words, there is a place. Their shows ownership. They’re is short for they are. Some examples:
“They’re too short,” muttered Eggworthy as he eyed the strips of bacon. (They’re means they are.)
“Why don’t you take some longer strips from their plates,” suggested Lola. (The plates belong to them — expressed by the possessive pronoun their.)
“My arm is not long enough to reach over there,” sighed Eggworthy. (There is a place.)
Company and business names sometimes sound plural (Saks, Lord and Taylor, AT&T, and so forth). However, a company is just one company and is, therefore, a singular noun. When you refer to the company, use the singular pronoun it or its, not the plural pronouns they or their. Take a look at these sentences, in which the singular pronouns are italicized:
Dombey and Sons often sends its employees on business trips.
It is offering a free vacation in the Caribbean to all its clerks.
If a singular pronoun sounds strange, you may adjust the sentence to refer to the employees. Sometimes you cut the pronoun entirely. Here's an example:
Strange: I returned the sweater to Sheldon & Daughters Department Store, and it offered me a refund.
Better-sounding but wrong: I returned the sweater to Sheldon & Daughters Department Store, and they offered me a refund.
Better-sounding and right: I returned the sweater, and the sales representative offered me a refund.
Remember: Pair singular pronouns with company names.
Two nouns — people and person — often confuse writers. People is plural and pairs with plural pronouns:
The people who scratched their names on the screen will be penalized.
Person is singular, as is any pronoun referring to person:
The person who left his or her chewing gum on the computer screen is in big trouble.
If you’re writing a sentence similar to the preceding example, you may be tempted to match their with person. Resist the temptation. In Grammar World, singular and plural don’t mingle, at least not legally.