Breakdown of Elle a annoncé que son compagnon se séparait d'elle.
elle
she
avoir
to have
de
of / from / any (in negative sentences) / about (concerning)
son
his/her/its
Questions & Answers about Elle a annoncé que son compagnon se séparait d'elle.
Why is se séparait in the imparfait here?
This is the sequence of tenses in action! The original statement was in the present tense: 'Mon compagnon se sépare de moi' (My partner is separating from me). Because the reporting verb a annoncé is in the past, that present tense shifts back to the imparfait (se séparait) in reported speech.
Why is it d'elle instead of putting a pronoun before the verb?
The verb is se séparer de (to separate from). With reflexive verbs that take de or à followed by a person, you cannot use standard object pronouns before the verb. Instead, you keep the preposition and add a stressed pronoun after it, like moi, toi, lui, or elle.
Since the subject is Elle (she), shouldn't 'her partner' use a feminine possessive adjective?