aufpassen

This is a separable verb. That means the auf part often flies to the end of the sentence. If you tell a friend to watch out, you say Pass auf!. If you are watching a dog, you use the preposition auf plus the accusative case. For example: Ich passe auf den Hund auf. It is simple but powerful. Just remember to split the verb when it is the main action. It feels natural once you do it a few times. Don't let the grammar scare you off.

Use it in the street when traffic is crazy. Use it in a meeting when the boss says something vital. It is perfect for babysitting too. If you are looking after someone’s laptop at a cafe, this is the word. You can also use it to warn someone about a social faux pas. It is very common in daily German life. You will hear parents say it to kids constantly. It is the soundtrack of a German playground.

Do not use it for 'paying' a bill. That is bezahlen. Also, do not use it for deep, romantic attention. If you want to say you cherish someone, aufpassen sounds too much like you are their bodyguard. It is about alertness, not necessarily affection. Avoid using it when you mean 'to listen' specifically. For that, use zuhören. It is also not for 'taking care' of a sick person in a medical sense. That would be pflegen.

Germans value order and safety quite highly. You will see signs everywhere telling you to aufpassen. There is a cultural sense of collective responsibility. If you see someone about to step into a puddle, you shout Pass auf!. It is not seen as rude. It is seen as helpful and direct. In Germany, being attentive is a sign of respect. It shows you are present and engaged with your surroundings. It is part of the 'Vorsicht' (caution) culture.

Pass auf! is the most common command. You might hear Aufpasser for a supervisor or a 'watchman.' Sometimes people say Pass bloß auf! when they are really serious. This adds a bit of a threat or a strong warning. There is also aufmerksam sein, which is more formal. But in the street, aufpassen is king. It is short, sharp, and effective. You will hear it in every train station in the country.