This is the 28th most frequent Russian word.
во
The Russian word "во" is a preposition meaning "in" or "into," used for emphasis or with certain cases.
The word 'во' is a preposition used here for locative purposes, indicating the place where the action occurs.
Во дворе дети играют в футбол.
In the yard, children are playing soccer.
Here, 'во' is part of the prepositional phrase 'во всё,' indicating the object of the belief within the sentence.
Он не верит во всё это.
He doesn't believe in all this.
'Во' is used in conjunction with the noun 'время' (time) to form the phrase 'во время,' indicating a temporal setting for the action.