Dar pra trás.

The imagery here is pretty straightforward and likely comes from everyday physical actions. Think about someone walking forward confidently, then suddenly stopping and stepping backward. This physical retreat mirrors the act of withdrawing from a commitment. It could also relate to old military or tactical movements where stepping back was a sign of retreat or surrender. In Brazil, where much of our language is shaped by daily life and practical metaphors, this physical action of stepping back perfectly captures the essence of breaking a promise or backing out of a deal. It’s a visual metaphor that’s easy to grasp, like seeing someone literally dar pra trás in a dance.

You use dar pra trás when someone is retreating from a commitment. It’s often used in the past tense to describe something that already happened. For example, Ele prometeu me ajudar, mas no final deu pra trás. (He promised to help me, but in the end, he backed out.) You can also use it in the present tense, though it’s less common. Não dê pra trás agora! (Don't back out now!) It’s usually directed at someone else’s actions, but you could theoretically say Eu não vou dar pra trás (I'm not going to back out) if you’re resisting the temptation to bail. Remember, it's about *withdrawing* from something already agreed upon.

• Friend A: Combinamos de ir ao cinema hoje à noite, né? (We agreed to go to the movies tonight, right?)
• Friend B: Ah, desculpa, não vou mais poder. Cansei. (Ah, sorry, I can't anymore. I'm tired.)
• Friend A: Sério? Você tá dando pra trás de novo? (Seriously? You're backing out *again*?)

• Scenario: You're planning a surprise party. Your cousin was supposed to bring the cake.
• You (texting): E aí, o bolo tá pronto? Não vai dar pra trás, né? (Hey, is the cake ready? You're not gonna back out, right?)

• Scenario: A business deal is about to be finalized.
• Client: Estávamos quase fechando, mas ele decidiu dar pra trás na última hora. (We were almost closing the deal, but he decided to back out at the last minute.)

Use dar pra trás when you want to describe someone breaking a promise or backing out of an agreement they previously made. It's perfect for situations where you feel let down or see someone being unreliable. Think about a friend who promised to lend you money but then suddenly can't. Or a business partner who agreed to a deal but then gets cold feet. It’s also useful when you want to warn someone *not* to back out. Não dê pra trás em cima da hora! (Don't back out at the last minute!) It fits well in informal chats, texts, and even in slightly more serious discussions when someone is clearly reneging on their word. It’s a very versatile phrase for situations involving broken commitments.

Avoid dar pra trás in very formal settings, like a legal contract signing or a high-level diplomatic negotiation. It sounds too casual and could be misinterpreted. Also, don't use it if someone is simply changing their mind *before* making a firm commitment. For instance, if you're just *thinking* about going to a party and then decide not to, you haven't dado pra trás yet. It implies a prior agreement. Using it here would be like saying someone backed out of a race they never even entered. Stick to situations where a promise or agreement was definitely made and then broken. It’s not for everyday indecision.

A common mistake is using it when someone is just hesitant or unsure, rather than actively withdrawing from a commitment. Another error is using it for something that wasn't a firm agreement.

✗ Eu pensei em ir na festa, mas depois não quis mais. Dei pra trás.

✓ Eu pensei em ir na festa, mas depois não quis mais. Decidi não ir. (This isn't backing out; it's just deciding not to go before committing.)

Another mistake is misconjugating the verb dar. Remember, it’s dar, not fazer or ir. So, fazer pra trás or ir pra trás are incorrect.

• Desistir: This means 'to give up' or 'to quit'. It's broader than dar pra trás and can apply to goals or challenges, not just agreements. You can desistir of running a marathon, but you dá pra trás on a promise to a friend.
• Voltar atrás na palavra: This literally means 'to go back on one's word'. It's a very close synonym and carries a similar meaning and weight.
• Quebrar a promessa: This means 'to break the promise'. It’s more specific to promises than dar pra trás, which can also apply to agreements or deals.

• Is dar pra trás always negative? Mostly, yes. It implies unreliability. You might use it humorously, but usually, it's a complaint.
• Can I use it for myself? Yes, but it sounds like you're admitting fault. Não quero dar pra trás (I don't want to back out) is more common.
• What if it's a small thing? It can be used for small things, like agreeing to grab coffee and then canceling last minute. The feeling is still about breaking a prior agreement.
• Is it formal? Definitely not. It's informal to neutral. Save it for friends and casual chats.