Conjunções Causais

These conjunctions introduce a subordinate clause. This clause explains the reason for the main action. It answers the question "Why?". Most causal conjunctions use the indicative mood. This is because reasons are usually seen as facts. You state a reality to explain another reality. Some patterns use the infinitive verb form. This happens when you use prepositions like por. The conjunction usually sits between two ideas. However, some can start the sentence. The choice depends on what you want to emphasize. It also depends on how formal you want to be. It is like choosing the right shoes. You wouldn't wear flip-flops to a wedding. You wouldn't use porquanto at a barbecue.

1. 1Start with your main statement or result.
2. 2Select a causal conjunction that fits your tone.
3. 3Add the clause that explains the reason.
4. 4Use the indicative mood for the verb.
5. 5Alternatively, start with the reason using como.
6. 6For informal reasons, use já que or visto que.
7. 7For academic writing, try uma vez que or dado que.
8. 8Ensure your comma placement is correct for clarity.

Use these in job interviews. You must explain why you left your last job. Use visto que to sound professional. Use them when ordering food. Maybe the kitchen is out of fish. Já que não há peixe, quero carne. Use them in arguments. Como não me ouviste, agora temos um problema. Use them in emails to professors. Uma vez que estive doente, peço um adiamento. Use them to express personal opinions. They make you sound more certain. They help you avoid sounding like a basic textbook. Real-world scenarios require real-world connectors. Even native speakers use these to avoid being repetitive. Think of it like a grammar traffic light. It tells the listener where the logic is going.

Do not use them if the cause is obvious. Redundancy is the enemy of good style. Avoid formal conjunctions in very casual chats. Using porquanto with your best friend is weird. It is like wearing a tuxedo to the gym. Don't confuse them with consecutive conjunctions. Causal explains the "why". Consecutive explains the "result". Do not use como in the middle of a sentence. In Portuguese, causal como lives at the start. If you put it in the middle, it looks like a comparison. Be careful with the preposition por. It needs the infinitive, not a conjugated verb. Por estar is correct; por estou is a disaster.

Mixing up porque and por que. It is the classic trap. Even natives fall into this one sometimes. Using como at the end of the sentence. It just doesn't work that way. Forgetting the comma before pois. Without it, the sentence feels breathless. Confusing visto que with visto (the past participle). They look similar but act differently. Using the subjunctive mood by mistake. Causal clauses almost always take the indicative. Overusing porque in every single sentence. It makes your Portuguese sound "flat" and repetitive. Think of variety as the spice of your speech.

Compare porque and visto que. Porque is the neutral, all-purpose hammer. Visto que is the precision screwdriver. It implies the reason is already known or visible. Contrast como and já que. Como is slightly more formal and starts sentences. Já que is conversational and can go anywhere. Look at pois. It often follows a comma and adds a logical explanation. It feels like adding an "afterthought" reason. Contrast this with porquanto. Porquanto is the ultimate formal king. You will see it in law books and old literature. Don't use it to ask for a coffee unless you want a confused waiter.