Não estou seguro

Use it just like you would in English. You can use it alone as a full sentence. You can also follow it with de que for more detail. For example: Não estou seguro de que ele venha. Remember that estou is from the verb estar. This describes a temporary state of mind. You aren't permanently unsure; you just are right now.

Use it in a business meeting when reviewing data. Use it with friends when choosing a restaurant. It works well when someone asks for directions. If you are texting, it’s a quick way to say "maybe." It is great for avoiding a firm commitment. It helps you stay polite while being cautious. Use it when you feel a bit of hesitation.

Don't use it if you are physically in danger. In that case, you would say não estou em segurança. Don't use it if you are 100% certain. That would just be confusing for everyone. Avoid it if you want to sound like a bold leader. Sometimes, being too "unsure" can make you look indecisive. Also, don't confuse it with não tenho certeza. That one is slightly more common in casual speech.

Portuguese speakers often value politeness and indirectness. Saying não (no) can sometimes feel too harsh. Using não estou seguro softens the blow of a negative answer. It shows you have considered the topic. It suggests you are a thoughtful person. In Brazil, people might prefer não tenho certeza. In Portugal, não estou seguro feels very natural and clear.

• Não tenho a certeza (Very common in Portugal).
• Não tenho certeza (The standard in Brazil).
• Não estou bem certo (Adds a bit more emphasis).
• Ainda não decidi (Specifically for when you haven't decided yet).
• Pode ser, mas não estou seguro (The classic "maybe but I'm not sure" combo).