Breakdown of Вчера он дотренировался до обморока.
он
he / it (for a masculine noun) / it (for a neuter noun)
вчера
yesterday
до
as far as, up to
дотренироваться
to train to exhaustion
Questions & Answers about Вчера он дотренировался до обморока.
How does the prefix до- change the meaning of the verb тренироваться here?
The combination of the prefix до- and the reflexive ending -ся forms a special pattern meaning to do an action to an extreme, usually negative, limit. Even though the base verb тренироваться already has the -ся ending, adding до- shifts the meaning from simply working out to training until a bad physical result occurs.
Why is the preposition до used right after a verb that already starts with до-?
This is a very common structural echo in Russian. Verbs that use the до-...-ся pattern to show an extreme limit are frequently followed by the preposition до to explicitly name that limit. The prefix tells us he reached a breaking point, and the preposition introduces exactly what that breaking point was.
What case is обморока in, and what is its dictionary form?
It is in the Genitive case, which is always required by the preposition до. The dictionary form (Nominative) is обморок, meaning a faint or a blackout.
Is there a difference between он дотренировался до обморока and just saying он тренировался до обморока?
Yes, there is a difference in emphasis. Without the prefix, you are just stating a fact about how long or hard he trained. By using дотренировался, you add a layer of emotion or judgment, emphasizing the extremity, foolishness, or inevitable negative outcome of pushing the action too far.