Alle vs. alles
The German words alle and alles can both be translated as all or everything, but they are not interchangeable. The key difference lies in whether you are referring to multiple, countable items or a single, uncountable concept.
Alle
A1The word alle means all or everyone. It is used with plural nouns to refer to all members of a specific, countable group of people or things. It can also stand alone as a pronoun meaning everyone. In colloquial German, alle can also mean empty or finished.
Alle Kinder spielen draußen.
(All the children are playing outside.)
Sind alle Gäste schon angekommen?
(Have all the guests arrived already?)
Ich habe alle meine Aufgaben erledigt.
(I have finished all my tasks.)
Er grüßte alle im Raum.
(He greeted everyone in the room.)
Entschuldigung, der Joghurt ist leider alle.
(Sorry, the yogurt is unfortunately all gone.)
Alles
A1The word alles is a pronoun that means everything. It refers to an abstract concept, a situation, or a collection of different things as a single, uncountable whole. It is treated as a singular noun.
Ich hoffe, alles ist in Ordnung.
(I hope everything is okay.)
Sie hat mir alles über ihre Reise erzählt.
(She told me everything about her trip.)
Das ist alles, was ich dazu sagen kann.
(That is all that I can say about it.)
Wir wünschen dir alles Gute zum Geburtstag.
(We wish you all the best for your birthday.)
Geld ist nicht alles im Leben.
(Money isn't everything in life.)
Summary
In summary, use alle for multiple, countable items or people (all of them, everyone). It answers the question Who? or Which ones?. Use alles for the singular, uncountable concept of everything. It answers the question What?.