I studied Latin in high school in 1976-78. From my best recollection, the verb tended to come after all the other words! So challenging. Ok, it was Virgil, so times have changed and they now write the words in this order. Just want to point out this is "modern." I would have learnd: Pater eius benignus est.
There isn't an English singular "their," at least not in formal, correct English. Granted, some have made casual use of a singular "their" in recent years where there is some ambiguity about the gender of the subject---and no doubt that practice will continue---but it isn't technically correct. For example, you may see something like "the critic failed to give their opinion of the performance," rather than the correct "the critic failed to give his or her opinion of the performance." The mixture of singular and plural references to the same (singular) actor is jarring, however, and I wouldn't recommend that kind of usage to a non-native speaker learning English for business or academic purposes.