Making Assumptions About the Past
When restoring a classic car (o clássico), you often have to guess what happened to it before it arrived in your garage. To express a strong deduction about the past—saying that something "must have" happened—use the present tense of the verb dever (must), followed by the perfect infinitive.
The perfect infinitive is formed using the auxiliary verb ter + the past participle of your main verb.
| The restoration of the classic must have been expensive. | O restauro do clássico deve ter sido caro. |
| They must have bought the bumper at the scrapyard. | Eles devem ter comprado o para-choques na sucata. |
| The sheet metal must have been very rusty. | A chapa deve ter estado muito enferrujada. |
Missed Opportunities and Regrets
You will also frequently need to talk about what "could have" or "should have" happened during a difficult project. For these unfulfilled actions, the structure is nearly identical, but you must shift the modal verb into the conditional mood.
To say what could have happened, use poderia (or the matching conditional form of poder), followed by ter + the past participle.
| The rust could have destroyed the sheet metal. | A ferrugem poderia ter destruído a chapa. |
| He could have repaired the rusty exhaust. | Ele poderia ter arranjado o escape enferrujado. |
To express regret or advice about what should have happened, use deveria (or the matching conditional form of dever), again followed by ter + the past participle.
| You should have finished the restoration of the upholstery today. | Tu deverias ter terminado o restauro dos estofos hoje. |
| We should have changed the classic's shock absorber. | Nós deveríamos ter trocado o amortecedor do clássico. |
| She should not have sold the upholstery and the bumper. | Ela não deveria ter vendido os estofos e o para-choques. |
Back in the Garage
Let's apply these structures using some additional mechanical vocabulary, such as o radiador (the radiator), o pedal (the pedal), and the verb soldar (to weld).
Notice how seamlessly you can switch between past assumptions and past regrets depending on the situation.
| The mechanic must have welded the radiator. | O mecânico deve ter soldado o radiador. |
| You should have bought a new radiator, so do not use the car! | Deverias ter comprado um radiador novo, por isso não uses o carro! |
| If you had removed the rust, I could have welded the pedal. | Se tivesses tirado a ferrugem, eu poderia ter soldado o pedal. |
