Boa sorte!

You can use it as a standalone exclamation. Just say Boa sorte! with a smile. If you want to be more specific, add com (with). For example, Boa sorte com o exame! (Good luck with the exam). It is incredibly flexible and requires very little grammar knowledge to master. Just remember that sorte is a feminine noun, so we always use the feminine adjective boa.

Use it whenever someone is about to do something nerve-wracking. It works perfectly when a friend is starting a new job. Use it when a colleague is giving a big presentation. It is also great for texting. Send a quick Boa sorte! before your friend's big game. It shows you are thinking of them and wishing them well. It is the ultimate social lubricant for supportive conversations.

Don't use it if someone has already finished the task. That would be awkward! In that case, use Parabéns (Congratulations) or Muito bem (Well done). Also, avoid using it in very grave or tragic situations. If someone is going to a funeral, Boa sorte is definitely not the vibe. It implies a gamble or a challenge, not a moment of mourning. Use your social intuition here.

Portuguese speakers are generally very supportive and expressive people. Wishing luck is a common social ritual. In Brazil, you might see people crossing their fingers while saying it. In Portugal, it is often said with a firm handshake or a pat on the back. While some cultures have superstitions about wishing luck, Lusophones embrace it. It is seen as a genuine gesture of kindness rather than a jinx.

If you want to sound more casual, you can say Sorte aí! (Luck there). This is very common in Brazil among younger people. For a more intense version, try Muita sorte! (Lots of luck). In the theater world, just like in English, some might say Muita merda! (Lots of sh*t). It sounds gross, but it is the equivalent of 'Break a leg!' Use that last one only with artist friends!