Tendo como base hipótese

You usually place this at the very beginning of your thought. Most of the time, you'll add the word a (the) or esta (this) before hipótese. For example: Tendo como base a hipótese de que vamos viajar... (Based on the hypothesis that we are going to travel...). You follow it up with a result or a secondary thought. It’s like a 'if-then' statement but with more flair. Don't forget to use de que if you are introducing a full action or clause right after it. It keeps the sentence flowing smoothly like a good Bossa Nova track.

This is your go-to phrase for the office, university, or any serious discussion. Use it in a meeting when you're projecting next year's budget. Use it when you're debating with a friend about a complex movie plot. It’s also perfect for writing formal emails where you need to sound organized. If you're trying to convince your partner to buy a new car by projecting gas savings, this phrase makes your argument feel much more 'official' and well-thought-out.

Avoid this when the situation is purely emotional or very casual. If you're at a bar and want to ask someone if they like their drink, saying Tendo como base a hipótese de que você gosta de gim... will make you sound like a robot or a very confused professor. It’s too heavy for light banter. Also, don't use it if you are absolutely certain about something. If the sun is out, don't say 'Based on the hypothesis that it is sunny'; just say it's sunny! Using it for obvious facts makes you sound a bit sarcastic or overly pedantic.

Portuguese speakers, especially in professional environments in Brazil and Portugal, value a certain level of formal structure in rhetoric. Using 'logic-gate' phrases like this shows that you are 'instruído' (educated). It stems from a long tradition of legal and academic writing that has trickled down into everyday professional speech. It’s a way to distance yourself slightly from an idea—if the idea fails, you can always say, 'Well, the hypothesis was wrong, not my logic!' It’s the ultimate intellectual safety net.

You might hear people say Com base na hipótese which is slightly more common in spoken Portuguese. Another variation is Partindo do pressuposto (Starting from the assumption), which is even more formal. If you want to keep it simpler, you can just say Supondo que (Supposing that). However, Tendo como base carries a weight of 'evidence' or 'foundation' that the others don't quite reach. It suggests you've actually looked at some data before opening your mouth.