Expressing Cause

Causal sentences explain the reason for the main action. They answer the question: 'Why?'. We use specific words called conjunctions to link these ideas. Some words are very common, like porque. Others are more formal, like visto que. The magic happens in the relationship between two parts. You have a 'Result' and you have a 'Cause'. For example: 'I'm tired' (Result) and 'I worked late' (Cause). You can say: Estou cansado porque trabalhei até tarde. Simple, right? But you can also flip the order. If you start with the cause, you use como. Como trabalhei até tarde, estou cansado. It feels like a grammar traffic light. Green means go with porque in the middle. Yellow means caution when using como at the start. Red means stop and think about formality with porquanto. It’s all about the flow of your conversation.

1. 1Creating these sentences follows a clear logical path. Follow these steps to build your own:
2. 2Identify the main event or the result first.
3. 3Choose a connector that fits your situation and tone.
4. 4Add the cause or the reason after the connector.
5. 5If starting with the cause, place the connector first.
6. 6Check if you need a comma for better flow.
7. 7Match your verb tense to the timeline of events.
8. 8For porque, the structure is: [Result] + porque + [Cause].
9. 9For como, the structure is: Como + [Cause] + , + [Result].
10. 10For por + infinitive: [Result] + por + [Infinitive Verb].

You will use these patterns in every possible scenario. Imagine you are in a job interview. You need to explain why you left your last job. You might say: Saí da empresa visto que procurava novos desafios. It sounds professional and measured. Or imagine you are ordering food in Lisbon. The waiter asks why you want a different side dish. You say: Prefiro salada, já que não como batatas. It’s friendly and clear. Even asking for directions involves cause. Como sou novo aqui, estou um pouco perdido. It gives context to your request and makes people more helpful. Use formal connectors in emails to your boss. Use casual ones like já que when chatting with friends. It’s like picking the right outfit for the occasion.

Be careful not to confuse cause with purpose. This is a very common trap for learners. Cause looks backward to the reason something happened. Purpose looks forward to a goal you want to achieve. If you say Estudo para passar, that is purpose. If you say Passei porque estudei, that is cause. Also, avoid overusing porque in every single sentence. It makes your Portuguese sound a bit repetitive and basic. Don't use very formal words like porquanto in a bar. Your friends will think you swallowed a legal dictionary! Finally, don't forget the comma when the cause comes first. Without it, the sentence can become a bit of a mess. Keep your cause and effect distinct and clear.

Yes, even native speakers mess this up sometimes. The biggest mistake is the position of como. You should only use como as a cause at the start. Saying Não fui à festa como estava doente sounds quite strange. It is much better to say Não fui à festa porque estava doente. Another slip-up is confusing porquê with porque. The one with the hat (porquê) usually comes at the end. The one without (porque) is for the middle of sentences. People also struggle with por + infinitive. They often try to put a full conjugated verb there. Remember: por + ser, not por + sou. Think of it like a puzzle piece. It only fits if the shape is exactly right. Don't force a verb where an infinitive belongs.

Let’s compare cause with explanation. Sometimes they feel identical, but there is a subtle difference. Pois is a great word for explaining a previous statement. It often acts like an 'afterthought' or a logical justification. Venha logo, pois o trem já vai partir. It’s slightly different from a direct cause like porque. Also, contrast cause with consequence using por isso. Cause: Estava frio, por isso usei casaco. Here, the cold is the cause and the coat is the result. Causal sentence: Usei casaco porque estava frio. It’s the same logic, just flipped around. Knowing how to toggle between these makes you much more fluent. You can emphasize the cause or the result as you wish. It gives you total control over the narrative of your speech.