Here I give the answer that I think can help you somehow, according to two sources:

According to wikitionary:

evrybody

Pronoun

All people. (Everybody takes a singular verb: Is everybody here?; Everybody has heard of it.)

Logically negates to not somebody.

Antonyms:

nobody, no one

Synonyms:

everyone

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everyone

Every person:

Is everyone ready to go?

• Everyone who ran in the race got a T-shirt.

• I was still awake, but everyone else (= all the other people) had gone to bed.

• Everyone but (= all the people except)

Logically negates to not someone.

Antonyms:

no one

Synonyms:

everybody

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Etymology

some + one

Indefinite pronoun

someone (plural some people)

some person.

Is someone there? – Is anybody here?

Logically related to anyone, everyone, and no one. Becomes no one via negation.

Synonyms:

anyone

anybody

somebody

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Pronoun

somebody

Some person:

• There’s somebody waiting to see you.

• Somebody’s car alarm kept me awake all night.

• somebody new/different etc.: I think they’re getting somebody famous to sing at the festival.

• If you can’t make it, we can always invite somebody else (= a different person).

• I bet she told Jill or Terry or somebody (= or a similar person)about it.

Logically related to everybody and nobody. Becomes nobody via negation.

Synonyms

someone

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NOW ACCORDING TO

PRACTICAL ENGLISH USAGE, by Michael Swan

every (one)

every + singular

Every is a determiner. We normally use it before a singular noun. If the noun is a subject, its verb is also singular.

every + singular noun

I see her evryday. (NOT … everydays.)

Every roomis being used. (NOT Every room are … )

every one without a noun

We can drop a noun and use it alone, if the noun has already been mentioned.

His books are great. Every one’s worth reading.

everybody etc

Everybody, everyone, everything everywhere are used with singular verbs, like every.

Everybody has gone home. (NOT Everybody have …)

When possessives and pronouns refer back to everybody/one, they can usually be either singular (more formal) or plural (less formal). Sometimes only a plural word make sense. Compare:

Has everybody got his or her ticket? (more formal)

Has everybody got their tickets? (less formal)

When everybody has finished eating, the waiters took away their plates. (NOT … hos or her plate)

Note that everyone (=’everybody’) does not mean the same as every one ( which can refer to things as people – see above).

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somebody, someone, anybody, anyone etc

1 -body and -one

There is no significant difference between somebody and someone, anybody and anyone, everybody and everyone or nobody ans no one. The forms with -one are more common; those with -body are a little more informal.

2 some- and any-

The differences between somebody and anybody, something and anything, somewhere and anywhere etc are the same as the differences some and any. Compare:

– There’s somebody at the door.

Did anybody telephone?

– Let’s go somewhere nice for dinner.

I don’t want to go anywhere expensive too expensive.

– Can I get you something to drink?

If you need something/anything, just shout.

3 singular

When these words are subjects they are used with singular verbs.

Everybody likes her. (NOT Everybody like her.)

Is everything ready? ( NOT Are everything ready?)

Somebody normally refers to one person . Compare:

There’s somebody outside who wants to talk to you.

There some people outside who wants to talk to you.

4 complementation

Somebody etc can be followed by adjectives or adverbial expressions.

I hope he marries somebody nice.

She’s going to meet someone in the ministry.

I feel like eating something hot.

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I hope that they would be useful to you,

Good Luck,

Two points, please.