Breakdown of Он признал свою вину.
он
he / it (for a masculine noun) / it (for a neuter noun)
свой
one's own
вина
guilt / fault
признать
to admit, to acknowledge (perfective)
Questions & Answers about Он признал свою вину.
Why must we use свою instead of его to mean "his"?
In Russian, when the subject of the sentence (он) is the owner of the object, you must use a form of the reflexive possessive pronoun свой. If you used его вину here, it would mean he admitted a different man's guilt.
Is признать вину the same as saying he confessed?
They are similar, but used differently. Признать вину specifically means "to admit guilt" or "to plead guilty" and takes a direct object. If you wanted to say "he confessed to a crime," you would usually use the verb сознаться, which takes the preposition в plus the prepositional case, such as он сознался в преступлении.
Does вину only mean "guilt" in a strict legal sense?
No, the base noun вина is used for both legal guilt and everyday fault or blame. For example, это моя вина is the standard way to say "it is my fault." Depending on the context of this sentence, it could mean he formally pleaded guilty in court or simply admitted he was in the wrong.
Why is the perfective verb признал used here instead of the imperfective признавал?
The perfective признал is used because admitting his guilt is presented as a single, completed action with a definitive result. You would use the imperfective признавал if you wanted to emphasize an ongoing process (he was in the process of admitting it) or a repeated action in the past.