Regular -ir Verbs in Preterite

In Portuguese, the preterite is used for actions that happened at a specific point in the past. It is not for things that used to happen habitually. It is for things that started and finished. Imagine you are at a job interview. You want to say, "I decided to change careers." That is a completed action. Or imagine you are at a restaurant and the waiter asks if you finished your meal. You would use this tense to say, "Yes, I finished." The beauty of regular -ir verbs is that they all follow the same pattern. Once you learn the endings for one, you have learned them for hundreds. It is like a master key for a whole wing of a building. You just need to swap the ending of the verb to match who did the action.

1. 1To conjugate these verbs, follow these three simple steps:
2. 2Start with the infinitive form of the verb, like abrir.
3. 3Chop off the last two letters, the -ir. This gives you the stem: abr-.
4. 4Add the specific preterite endings to that stem based on the person.
5. 5Here are the endings you need to memorize:
6. 6Eu (I): -i (Example: Eu abri - I opened)
7. 7Tu (You, informal): -iste (Example: Tu abriste - You opened)
8. 8Você/Ele/Ela (You/He/She): -iu (Example: Ela abriu - She opened)
9. 9Nós (We): -imos (Example: Nós abrimos - We opened)
10. 10Vocês/Eles/Elas (You all/They): -iram (Example: Eles abriram - They opened)
11. 11Think of the -iu ending for he/she like a quick slide. It sounds a bit like the "u" in "music" but shorter. Also, notice that the nós form is exactly the same as the present tense. Yes, even native speakers rely on context to know if you mean "we open" or "we opened." It is a grammar two-for-one deal!

Use this tense when the action is totally over. Here are some real-world scenarios:

• Reporting a task: "I finished the report yesterday." (Eu decidi terminar o relatório ontem.)
• Socializing: "We met at the cafe." (Nós nos reunimos no café.)
• Travel: "The train left at noon." (O comboio partiu ao meio-dia.)
• Daily life: "I opened the window because it was hot." (Eu abri a janela.)

You will often see this tense paired with time markers. Look out for words like ontem (yesterday), anteontem (the day before yesterday), or na semana passada (last week). These words are like green lights telling you to use the preterite. If you can point to a specific time on a calendar when it happened, this is usually your go-to tense.

Do not use this tense for "used to" actions. If you want to say, "I used to live in Lisbon," the preterite is not your friend. That requires the Imperfect tense because it was a continuous state. Also, avoid using it for actions that were happening when something else interrupted them. For example, "I was opening the door when the phone rang." The "was opening" part is not preterite. The preterite is for the "phone rang" part because that was a sudden, completed event. Think of the preterite as a snapshot photo, while other past tenses are more like a long video. If it feels like a single point in time, use the preterite. If it feels like a blurry habit, stay away!

One big mistake is confusing -ir endings with -er endings. While they are similar, the eu form for -ir verbs is always -i, not -ei. If you say Eu abrei, people might think you are trying to invent a new language. Another common slip-up is the vocês/eles ending. Make sure it ends in -iram (with an 'm'). If you use an 'o' (like -irão), you have accidentally teleported into the future tense! That is a mistake that might make your friends think you are a time traveler. Lastly, don't forget that nós stays the same as the present. Don't try to add extra letters to make it look "more past-tense." Keep it simple.

Let's compare -ir verbs with -er verbs in the preterite.

• For -er verbs (like comer), the ele/ela ending is -eu (ele comeu).
• For -ir verbs (like abrir), the ele/ela ending is -iu (ele abriu).

It is a tiny difference, but it matters. Also, compare -ir with -ar verbs. The -ar verbs use -ou for the third person (ele falou). The -ir verbs are actually quite consistent and often feel "sharper" in their pronunciation because of the "i" sound. If you know Spanish, be careful! The tu form in Portuguese is -iste, while in Spanish it is -iste as well, but the nós form in Portuguese is -imos, which is the same as the present, just like in Spanish. It’s a rare moment where knowing another language actually helps instead of confusing you.