"I want to know everything."
Translation:Я хочу знать всё.
In the Nominative все means all people and всё means all things. English, on the surface, prefers to use "every" to state something about "all" objects, which conveniently lets you render «все» as "everyone" (only plural) and «всё» as "everything" (which is singular).
- pay attention to the context when dealing with authentic material. In print Ё is rarely used, primarily to resolve ambiguity. Sadly, it is not in much use EVEN to resolve ambiguity (все/всё) or the pronunciation of words a speaker may not know (Шрёдингер). However, any decent book for a foreign learner will consistently use Ё and will often show stress, too (the latter will also hold for books for little kids).
You can also take a step back and try to look at the whole paradigm of the adjectival modifier весь (all, entire):
- Nominative: весь (m), вся (f), всё (n), все (pl)
- Genitive: всего (m), всей (f), всего (n), всех (pl)
- Prepositional: всём (m), всей (f), всём (n), всех (pl)
And so on. Such a table has all necessary forms: we use neuter singular forms for "all stuff" and plural forms for "all people". Come to think of it, this corresponds well to how, for instance, impersonal sentences show number and/or gender agreement:
- Тогда было холодно. = It was cold then. (undefined subject standing for forces of nature is inanimate and takes neuter)
- Меня зовут Василий. = lit. "They" call me Vasiliy. (unspecified 3rd person agents are people)