"He took care of everything after they died."
Translation:Lui si prese cura di tutto dopo che morirono.
Why is it 'si prese', rather than 'e prese'? This is active and I don't see how it could be reflexive and it's certainly not impersonal...
Prendersi cura di is an idiom meanding "to take care of" or "to look after" something. Prendersi is the reflexive for of the verb prendere, which basically means "to take for/upon oneself" (as opposed to taking something else).
When you conjugate prendersi, you put tge reflexive pronoun before the verb. In this case, as the subject is lui, the reflexive pronoun is si.
The verb itself is conjugated the same as prendere. Prese is the passato remoto (remote past) form of the 3rd person singular of the verb.
Thus, when you put it all together, Lui si prese cura di tutto means "He took care of everything" or "He saw to everything". It isn't the present tense (that would be si prende cura di tutto).
I you want to say "I took care of everything" in the remote past, you would say "Mi presi cura di tutto.*
I hope I helped answer your question?
"Take care of" is shown as "pensare a" in dictionaries but this is not accepted by DL.