Because 'жена́' is a feminine noun, and 'свою́' is a feminine form.
If there was a masculine word, you’d use 'своего́':
- Она́ лю́бит своего́ му́жа. 'She loves her husband.' (because му́ж is a masculine noun)
«Ему́ нра́вится его жена́, но о́н её не лю́бит».
(Since with «нра́вится», the subject of the sentence is «жена́» and not «он», we can't use «своя́» because «своя́» means the owner is the same as the subject of the sentence.)
Свой is the Russian reflexive possessive pronoun. It is used like Мой (my), and has the same forms.
It is used when the owner of something is the subject of the sentence clause. (Its use is required in the 3rd person, and optional in the 1st and 2nd. Although it is almost always used if the subject is ты).
For example, Иван любит свою собаку - Ivan loves his (own) dog.
Common questions about this sentence:
Why is "likes" not accepted? - When used with people, любить means "love" and нравиться means "like". (A better explanation: https://forum.duolingo.com/comment/11754722)
Why свою? - Свою is the accusative singular feminine of свой.
Why жену? - Жену is the accusative singular of жена.
Why accusative and not genitive? - The confusion here may have been caused by seeing a similar sentence with a masculine noun (e.g. "Он любит своего мужа") and interpreting it as genitive. What's going on here is that specifically for ANIMATE (living, moving) masculine nouns, such as people or animals, the accusative case will match the genitive (with everything, including adjectives and numerals). For INANIMATE masculine nouns, the accusative case will match the nominative. Hence why even though брат and стол are both masculine, you say:
"Я вижу своЕГО братА"
"Я вижу своЙ стол".
If i translate this from Russian i could have accidentally cause a homicide.. it still feels like "he loves your wife" or "he loves his(another guys) wife" one thing i am sure that this devoted guy is a cheater.
Okay you're a little off base there, all direct objects conjugate as accusative.
What I think you're saying is why isn't the accusative form the same as the genitive. Well that rule holds for masculine singular words but not for feminine or neuter singular. In fact, feminine words usually have clearly separate forms for nominative, accusative and genitive so there's little confusion.