kompetenta

Three adjectives here look interchangeable in a dictionary and are not. Kapabla is raw can-do: you are physically or mentally able to perform the thing. Lerta is skill in the hands - deft, nimble, good at doing. Kompetenta is about knowledge and standing: you know the field well enough that your judgement in it counts. A child can be lerta; only somebody with training is kompetenta.

Note the preposition. Kompetenta pri is the ordinary one - competent in or about a subject: kompetenta pri juro. You will also see kompetenta en, and neither will confuse anybody, but pri is the safer default because it points at a topic rather than a place.

The second meaning is the one English has almost lost. In legal and administrative Esperanto, kompetenta means having authority over: la kompetenta tribunalo is the court that has jurisdiction, not the court that is good at its job. The noun kompetenteco carries both senses, competence and jurisdiction, so read it from the sentence. English keeps the old value only in fossilised phrases, which is exactly the pattern the false friends article describes: the continent held on to the Latin value, and English wandered off with it.