Questions & Answers about Konstruktor myśli o tym, gdzie zbudować lunapark.
Why do we need o tym before gdzie? Can't I just say myśli o gdzie like in English?
Polish generally avoids putting prepositions directly in front of question words. Instead, you use the 'dummy' pronoun to after the preposition, decline it to match the case the preposition requires, and then add your question word. Since myśleć o (to think about) takes the locative case, to becomes tym. You are literally saying 'thinks about this, where...'.
Is the comma between tym and gdzie strictly necessary?
Yes. In Polish, you must always put a comma before a subordinate clause, which includes indirect questions starting with words like gdzie, co, jak, or czy.
Why use the infinitive zbudować here instead of a conjugated verb?
Just like in English ('where to build'), you can use an infinitive in a Polish indirect question when the subject of both parts is the same, or when the action is meant generally. If you wanted to specify someone else building it, you would use a conjugated verb, for example: o tym, gdzie mają zbudować (about where they are supposed to build).
Why doesn't the word lunapark change its ending here?