Fale mais devagar

You can use it exactly as it is. Just drop it into the conversation when you feel lost. If you want to be extra polite, add a por favor at the end. It works perfectly in person, over the phone, or even in voice notes. It is a functional tool, not a complex idiom.

Use it at the bakery when the clerk lists five types of bread in two seconds. Use it in a meeting when your colleague gets too excited about spreadsheets. It is perfect for taxi drivers who love to tell long stories. Basically, use it whenever your brain's translation software starts to smoke. It shows you are engaged but just need a little help.

Do not use it if someone is already speaking like a snail. It might come across as sarcastic or a bit rude then. Avoid using it in a shouting match; it won't help the mood. Also, do not use it during a formal speech or a movie screening. That is just common sense, right? Keep it for active, two-way conversations.

Portuguese speakers, especially in Brazil or Portugal, are famous for their passion. This passion often translates into high-speed talking and cutting off word endings. In Portugal, the vowels can disappear entirely at high speeds. In Brazil, the rhythm is musical but can be very fast in cities like Rio. Asking someone to slow down is seen as a sign that you actually care about what they are saying.

You might hear Pode falar mais devagar? which means 'Can you speak more slowly?'. This is slightly softer and more of a request than a command. Another common one is Mais lento, por favor. If you are in a very casual setting with friends, you might just say Calma, calma! while laughing. This signals them to chill out with the speed.