the use is a little complicated, but still: Everything is usually a pronoun - a quantifying pronoun. That means it can take either subject or object position : Everything is fine. / I finished everything All on the other hand is a quantifier which can have various grammatical functions : - Adverb : used to modify a preposition (all over, all round, all through etc) or adjective (all dirty, all right) etc : He was reading all through the night / He's made it all right. - Determiner : All the people cheered. - Pronoun : We were provided with all we needed That is mostly it.. but try to use some grammar books to feel the difference

All:(used in referring to quantity, extent, or duration): all the cake; all the way; all year Everything: particular of an aggregate you can say all people but everything people.

=) The pronoun ALL used as a noun pronoun and as an adjective pronoun . ALL is used as a noun pronoun is singular when it means "everything", "the whole thing" - All's well that ends well All used as a noun pronoun is plural when it means 'eve- rybody', 'the total number of persons, animals or things.' e.g. All are welcome. Everything can be used only of things and also takes a sin- gular verb but it cannot have the genitive case form. for instance, one can't have everything. Can we substitue these pronouns - All and Everything in this sentence, for example, I'll tell you everything tonight.

In what context Doch? :)