I'm currently on lesson 3.10, and was checking the conjugation of certain verbs on other sites; it appears that the subject pronouns for 3rd person singular are “egli” and “ella”, whereas earlier in the course (e.g. lesson 1.9) we were given “lui” and “lei”.
Going by a conversation in reddit, it appears that the former pair are the “correct” pronouns, the latter pair being object pronouns or used with prepositions. However, lui and lei may be used in informal speech as subjects. Is that correct?