Hypothetical Past Conditions Using

This grammar deals with two things: an imaginary cause and an imaginary result. Both happened (or didn't happen) in the past. Since the past is fixed, these sentences are purely hypothetical. You are creating a parallel universe. In this universe, the facts are different. For example, in reality, you didn't study. You failed the test. In the hypothetical version, you did study. You passed the test. To do this, you need two clauses. The first clause starts with se (if). It sets the condition. The second clause shows the result. It is like a movie script for a life you didn't lead. Yes, even native speakers mess this up sometimes! Don't worry if it feels like mental gymnastics at first.

1. 1Building these sentences requires a "compound" approach. You need auxiliary verbs and past participles. Follow these steps to build your sentence:
2. 2Start with the word se (if).
3. 3Use the auxiliary verb ter in the Pretérito Imperfeito do Conjuntivo. For the "I" form, this is tivesse.
4. 4Add the particípio passado (past participle) of your main verb. Examples: feito, ido, comprado.
5. 5This creates the "If" part: Se eu tivesse feito... (If I had done...).
6. 6For the result, use ter in the Condicional. For "I", this is teria.
7. 7Add the particípio passado of the result verb. Examples: ganhado, chegado.
8. 8This creates the result: ...teria ganhado. (...would have won.).
9. 9Putting it together: Se eu tivesse estudado, teria passado. It is like building with Lego blocks. Each piece has a specific place. Use tivesse for the condition. Use teria for the result.

Use this pattern when reality didn't go your way.

• Regrets: Use it for things you wish you did. "If I had told the truth..."
• Relief: Use it for disasters you avoided. "If I hadn't worn a seatbelt..."
• Job Interviews: Talk about missed opportunities or different choices. "If I had known about this role sooner..."
• Travel Woes: Perfect for airport stories. "If the train had arrived on time..."
• Social Relatability: Sharing "almost" stories with friends. "If I had won the lottery, I would have invited you!"

Think of it as the grammar of "almost." It adds color and emotion to your stories. It shows you understand the nuances of life.

Don't use this for things that might still happen. If the door is still open, use the future subjunctive. For example, "If I win tomorrow" is different from "If I had won yesterday." Also, avoid it for general truths. "If it rains, the ground gets wet" uses simple tenses. This complex structure is strictly for the "closed" past. If the event is over, this is your tool. If the event is ongoing, use the present hypothetical instead. Using this for a future event will confuse your listener. It would be like trying to use a map of Lisbon in Porto. It just doesn't fit the terrain.

Many learners use the wrong tense after se.

• Mistake: Using se eu tinha (indicative).
• Correction: Always use se eu tivesse (subjunctive).
• Mistake: Forgetting the auxiliary verb. You cannot say Se eu estudado.
• Mistake: Mixing up tivesse and teria. Remember: tivesse stays with the se.

Think of se and tivesse as best friends. They are always together. Another common slip is using the wrong past participle. Irregular verbs like fazer (made) become feito, not fazido. Keep a list of irregulars handy. It is like a grammar traffic light. Red means you used the indicative—stop and fix it!

Compare this to the "Second Conditional."

• Second Conditional: Se eu ganhasse a lotaria, compraria um carro. (If I won now/in the future).
• Third Conditional: Se eu tivesse ganhado a lotaria, teria comprado um carro. (If I had won in the past).

The first one is a dream for the future. The second one is a dream about a past event. One is still possible. The other is impossible because time has passed. In English, we say "If I were" vs "If I had been." In Portuguese, the difference is between a single verb (ganhasse) and a compound one (tivesse ganhado). It is the difference between "maybe tomorrow" and "alas, yesterday."