Questions & Answers about Ellos se han casado y se han mudado hoy.
Why is the word se before han in both verbs?
When using the present perfect (like han casado), any reflexive pronouns like se must go directly before the conjugated form of the helper verb haber. You cannot put the pronoun between haber and the past participle, and you cannot attach it to the end of the participle.
Why do we repeat se han for the second verb (y se han mudado)? In English we just say 'and moved'.
In Spanish, it is much more common and grammatically natural to repeat both the reflexive pronoun (se) and the conjugated helper verb (han) when connecting two present perfect actions with y (and).
Why are the verbs for 'marry' and 'move' reflexive in this sentence?
In Spanish, changing your own marital status uses the reflexive verb casarse (to get married). Similarly, moving your residence or changing where you live uses the reflexive verb mudarse (to move). Without se, these verbs would mean you are marrying off someone else, or moving an object.
Why use the present perfect (han casado) instead of the simple past (casaron) since the action is already done?
The present perfect is used here because of the word hoy (today). In Spanish, when an action happens in a time period that isn't over yet (like today, this week, or this month), you use the present perfect to show that the time frame still connects to the present moment.