In English, we often link a preposition directly to a question word: "I'm thinking about where to go" or "It depends on whether it works."
In Polish, a preposition cannot directly introduce an indirect question. Instead, you must insert a correlative pronoun—a form of to (this/it)—to act as a bridge. The form of to depends on the grammatical case required by the preposition.
Thinking and talking: o tym
Verbs like myśleć (to think) and rozmawiać (to talk) pair with the preposition o (about), which requires the Locative case. Because of this, to becomes tym.
The structure is: [Verb] + o tym, + [question word]... (literally: "...about this, [question word]...").
Depending on: od tego, czy
The verb zależeć (to depend) pairs with the preposition od (on/from), which requires the Genitive case. This turns to into tego.
When your indirect question is a "yes or no" question, use the word czy (whether / if).
Other cases: nad tym and na to
This bridging rule applies across the board, no matter which case the preposition demands:
- nad (over/about) requires the Instrumental case, so zastanawiać się nad (to wonder about) is followed by tym.
- na (on/to) requires the Accusative case, so uważać na (to pay attention to) or mieć wpływ na (to have an influence on) is followed by to.
Engineering the rollercoaster
Here are a few more examples of correlatives in action as we design the perfect theme park ride. Notice how the preposition always dictates the shape of the bridge before the question word!
