"The teacher reads stories, written by his friend."
Translation:Учитель читает рассказы, написанные его другом.
Perhaps, you could say that, although when a possessive reflexive pronoun gets to another clause, it sounds awkward as too independent. I've never heard of such a rule though. "Учитель читает рассказы своего друга" would be completely fine.
Свой means that the subject of action possesses the object. It's commonly used to avoid an ambiguity with possession, like: "Here are Tom and Jim. Tom is talking to his wife." Whose wife is Tom talking to, Tom's or Jim's? We can't know. But in Russian we can using "свой": Вот Том и Джим. Том говорит со своей женой. - жена Тома, Tom's wife. Sometimes "свой" doesn't resolve an ambiguity but adds it, then other possessive pronouns should be used: "Я нашел брата в своём доме" - we don't know whether the house is his or mine, use его (his) or моём (my). But in colloquial speech such mistakes are more than common among natives.
When it's clear who possesses the object, those pronouns are interchangeable, although the personal possessive pronouns emphasize the possession: "Я люблю мою жену" vs "Я люблю свою жену".
Ok. What we've learned so far is that свой refers back to the subject of the sentence. But here two native speakers say it would refer to the object of the main clause (which is the implicit subject of the subordinate clause), so it seems more complicated than that. Would it be fair to say "Don't use свой across clauses"? But I've seen some examples here where it was...
For “his” to be translated as some form of «свой» the noun it modifies (in the given sentence it is “friend”) has to be an object of the verb or preposition linked with the subject of the main clause. In the given sentence, “his friend” is NOT an object of “reads”, hence the appropriate translation is «его другом» rather than «своим другом».
When I said “linked”, speaking of the verb, I meant the predicate of the subject, e.g. Учитель читал свои рассказы (читал is the predicate of учитель). Speaking of a preposional phrase, it can be any preposition+possessive adjective+noun phrase modifying another noun: женщина со своим сыном. That other noun, however, has to be the subject, other wise the use of свой will be wrong: я видел женщину с её сыном = I saw the woman with her son, я видел женщину со своим сыном = I saw the woman with my son. An example of using свой in a subordinate clause: «Я видел дом, который он построил своими руками».
Only imperfective verbs have present tense. Whenever you speak about a regular or repetitive action or unfinished action in progress or a current state, you need an imperfective verb. A future or passed action viewed as a one-time event —particularly, an action applied to a definite object — is described by a perfective verb.
A written short story is called рассказ. A written long story (over 50 pages) is called повесть. The word “stories” is translated as истории when it is used as the object of verbs such as слышать (hear), слушать (listen to) or рассказывать (tell), in other words, when it is verbal stories we are talking about. We can also say, «Он рассказал/поведал нам свою историю» (“He told us his story”) and «Он пишет историю своего города» (“He is writing the history of his city”). If anyone tells me stories and I write them down, they become истории, записанные мной, but if I am the author, истории become рассказы. So, no, for the translation of the given sentence истории should not be accepted.