Which is correct?
“Did somebody lock the door?”
“Did someone lock the door?”
Answer: They are both correct, but it depends on the situation.
Both “somebody” and “someone” are indefinite pronouns.
“Somebody” is informal. “Someone” is more formal.
For more detailed information, read Word Genius’ take on the issue:
Somebody vs. Someone
“Somebody” is an indefinite pronoun. It refers to an unnamed, unspecified person. Maybe you know the name, but it isn’t relevant to the situation. If you are living in a home with several people, you might say, “Did somebody lock the door?”
You know the names of the people who live with you. But it isn’t important who locked the door. It’s just important that it was done by somebody.
“Someone” is also an indefinite pronoun, but it has a slightly different use. “Someone” is considered to be slightly more formal than somebody. If you were writing a term paper, or a professional email, it would make more sense to use the word “someone” over “somebody.”
“Someone will come get you when the doctor is ready.”
“Can somebody bring a bag of ice for the party?
A helpful trick to remember which word to use is that someone has an “n” in it, as does the word “professional.” Somebody doesn’t have an “n,” and it doesn’t need to be used in more professional settings. Aside from the formal/informal connotations of the two pronouns, they can be used interchangeably.
Nobody vs. No One
The distinction between “nobody” and “no one” is the same as the “some” pronouns. The two words are synonyms with slight nuances for the usage of one over the other.
“Nobody” is a pronoun, just like “somebody,” and it means not any person. Although “nobody” is generally singular, it’s also sometimes used as a plural indefinite pronoun, which just means that it doesn’t specify whether plural or singular, and it doesn’t indicate gender.
“Even though I planned my party months in advance, nobody has RSVP-ed yet.”
You could easily substitute “no one” into the above sentence, and it wouldn’t change the meaning, aside from indicating that the setting for the sentence was a more formal one.
“No one will be in the office over the holiday weekend.”
Pronoun rules are made to be broken. If you are writing a paper for a professor or a formal letter, “no one” and “someone” might seem more appropriate. However, the “-body” pronouns will still get your meaning across. Also, the same can be said for anyone/anybody and everyone/everybody. In all of these pronoun choices, the words that have “body” in them are more informal.