Breakdown of Vi låter kollegan använda sin befogenhet att vägleda sin grupp.
vi
we
att
to
kollegan
the colleague
sin
his/her/its/their own (en-word)
Questions & Answers about Vi låter kollegan använda sin befogenhet att vägleda sin grupp.
Why do we use sin befogenhet here when the main subject of the sentence is vi?
This is an object-controlled reflexive. While vi (we) is the grammatical subject of the main clause, kollegan (the colleague) is the object being allowed to do something. Because kollegan is the one performing the action of the infinitive verb använda (to use), they are the logical subject of that action. Therefore, sin refers back to kollegan, not vi.
Does the second sin in sin grupp also refer back to kollegan?
Yes. The phrase att vägleda sin grupp (to guide his or her group) is another infinitive clause where kollegan is still the logical subject doing the guiding. Since it is the colleague's own group, we use the reflexive sin. If it were someone else's group, we would use hans, hennes, or deras.
Why is there no att before använda, but there is one before vägleda?
The verb låta (to let or allow) takes a bare infinitive without att, very much like the English verb let. However, befogenhet att vägleda (authority to guide) works differently; here, att vägleda is an infinitive phrase modifying the noun befogenhet, which requires the infinitive marker att.