When organizing a VIP security detail, you need to prepare for every contingency. In English, we express this using "in case..." In Polish, the equivalent phrase is na wypadek, gdyby (literally: "on the eventuality, if").
The gdyby rule
Because this expression uses the conditional word gdyby (if), the verb that follows it must always be in the past tense.
| Let's prepare the armored convoy in case there is an assassination attempt. | Przygotujmy opancerzony konwój na wypadek, gdyby był zamach. |
| Give the female boss the bulletproof vest in case the sniper is there. | Daj szefowej kuloodporną kamizelkę na wypadek, gdyby snajper tam był. |
Purpose vs. precaution
For a specific, intended goal, use żeby (so that / in order to) followed by an infinitive verb:
| The bodyguard wears an earpiece to hear the president. | Ochroniarz nosi słuchawkę, żeby słyszeć prezydenta. |
To prepare for a hypothetical danger, use na wypadek, gdyby followed by a past-tense verb:
| The bodyguards are planning a retreat through the rear exit in case someone enters here. | Ochroniarze planują odwrót przez tylne wyjście na wypadek, gdyby ktoś tu wszedł. |
| The bodyguard is walking slowly in case a sniper is nearby. | Ochroniarz idzie powoli na wypadek, gdyby w pobliżu był snajper. |
Commas
Typically, a comma splits the phrase: na wypadek, gdyby. However, if you tack the entire precaution onto the end of a sentence as a separate clause, the comma can go before the whole phrase: , na wypadek gdyby. In both cases, the verb remains in the past tense.
| Take the bulletproof vest and the earpiece, in case there is an assassination attempt. | Weź kamizelkę kuloodporną i słuchawkę, na wypadek gdyby był zamach. |
| Let's evacuate through the rear exit in case the sniper sees us. | Ewakuujmy się przez tylne wyjście na wypadek, gdyby snajper nas widział. |