Questions & Answers about Podobnie jak jego brat, on jest lekarzem.
Why use podobnie jak instead of just jak for "like"?
While jak by itself means "like" or "as", adding podobnie (which means "similarly") emphasizes the strong shared situation between the two subjects. It translates best to "just like" or "similarly to".
Why is lekarzem in the instrumental case here?
In Polish, when you use the verb być (to be) to state someone's profession, identity, or role, the noun that follows must be in the instrumental case. The nominative dictionary form is lekarz, so it becomes lekarzem.
Could we use the reflexive pronoun swój instead of jego?
No, you need to use jego here. The word swój (one's own) always refers back to the subject of the clause it is in. In the phrase podobnie jak jego brat, the brother is the subject of that specific comparison. If you used swój, it would confusingly refer to the brother's own brother.
Why doesn't brat also take the instrumental case to match lekarzem?
The phrase podobnie jak jego brat is essentially a shortened version of "Just like his brother is". Because brat is the subject of that hidden, implied verb, it stays in the nominative (subject) case.