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Why do we say “Se me olvidó” instead of “Yo olvidé” in Spanish?

Written by Virginia Orozco | Sep 5, 2025 3:37:03 PM

Do you know the verb “olvidar”? It means “To forget”. Let’s say you perfectly understand it. You know how to conjugate it: Yo olvido, Tú olvidas… on and on. You got it, right?

But then, you hear a native Spanish speaker say “Se me olvidó el libro”.

Wait… What?! You might ask yourself “What happened to Yo olvidé el libro?”

Don’t worry. No one is rewriting the Spanish rules. These are called accidental “se” constructions. And it’s easier than it seems. Just take a minute to learn about it, and it’ll all make sense!

 

What are Accidental “Se” Constructions?

Let's put it in simple terms. This is just a type of sentence used to express unintentional or accidental actions or events.

There are a few more cases when you can use accidental “se” constructions. For example:

  • For things you didn’t mean
  • For less personal, kind of impersonal phrases
  • For events that weren’t your fault, and to soften the blame
  • For things out of your control.
  • For things you weren’t responsible for (or indirect responsibility)
  • For actions that happened to you. Instead of you doing them.

All of these situations have something in common. You’ll want to avoid putting all the focus on you, or the subject of the sentence.

Does this sound confusing? It’s okay! It’s easier than you think. And with this guide, you’ll see exactly how to start doing it yourself.

Now, let’s take a closer look at how these sentences work.

The “Se” formula

To fully understand these sentences, we have to pay attention to the structure. As a rule, this type of impersonal phrases follow this formula:

Se + indirect object pronoun (me/te/le...) + verb (in 3rd person, matching the subject in number) + subject

Notice how it shows clearly on our first example: Se + me + olvidó + el libro.

Take a look at these examples that still follow that exact same formula:

  • Se te olvidó el teléfono
  • Se le olvidaron las llaves
  • Se nos olvidó la fiesta
  • Se les olvidó la reunión

Now, we know what this is, and how to write it. But why do Spanish speakers use the accidental “se” construction at all?

Why do Spanish speakers use it?

It’s actually very simple. The main reason is right there on its name. It’s for accidents! If you say “Se me olvidó el libro” it’s clear that it was an accident. Because the focus is on the action, not on your person. It’s the opposite of “Yo olvidé el libro.”

When you structure the sentence this way, it puts the focus on the object or the event. Not on the subject. It says hey, the book was forgotten! Instead of oops, it’s my fault, I forgot the book.

So, now you know. If you want to show indirect responsibility, lack of intent, or that it was an accident… Start using accidental “se” constructions!

What other verbs work this way?

Yes, you can use other verbs with accidental “se” constructions. We call them pronominal verbs, also known as object-focused verbs. As the name says, they put the emphasis on the object, instead of the subject. That’s the core of today's topic!

The most important ones you should know are:

  • Romper (to break)
  • Perder (to lose)
  • Caer (to drop)
  • Quedar (to leave behind)

Now, if you combine them with the formula we just studied, you can get sentences like these:

  • Se me rompieron los platos
  • Se nos perdió el gato
  • Se te cayeron los lápices
  • Se le quedó la tarea

That’s fantastic! Knowing the formula and these object-focused verbs, you’ve unlocked endless possibilities to form these types of sentences!

Now that you know more about the indirect responsibility of these sentences, it’s time to go farther. 

 

 

Tips to use accidental “Se” constructions

By this point you have all the tools you need to start using these sentences. You know what they are and how they are used. You also have the secret formula and other object-focused verbs you can use. All you need next are these tips:

Change your perspective

This type of sentence can be a little confusing for English speakers. It’s completely normal to think first of “I forgot” and translate it to “Yo olvidé”. So, the key to move on to “Se me olvidó” is actually a shift in perspective.

These sentences are all about passive meaning, you know? That means you must change the focus away from the subject and toward the object. If you’re wondering how exactly to do this, these questions can help you!

Stop thinking “Who did it?” in regards to the event you’re describing.

Start thinking “What happened?” and it’ll help you form these sentences.

Avoid common mistakes

Let’s make things a little clearer. If we take a closer look at some common mistakes, you’ll know when to avoid them. For example:

  • “Yo se me olvidó el pasaporte” → Wrong. You don’t need to add “Yo” at the beginning → “Se me olvidó el pasaporte”
  • “Se te olvidó lápiz” → Wrong. It’s missing the article in front of the subject → “Se te olvidó el lápiz”
  • “Se nos olvidó los regalos” → Wrong. The verb has to match in number the subject, if it’s singular or plural → “Se nos olvidaron los regalos”

Learn in chunks instead of single words

You see, there’s a difference between these two strategies. Learning “se” “me” and “olvidó” it’s three times the effort of learning it all at once. Instead of focusing on each separate word, you can learn this knowing the full thing, “se me olvidó”, means “I forgot.”

You don’t actually need to learn and memorize all the rules to start speaking Spanish. That can wait. It’s best to put your effort into learning full sentences that you can start using in your everyday conversations.

And this has a lot to do with our next point, you’ll see.

Avoid direct translations

This is always great advice when learning a new language. But especially when it comes to this kind of sentence structure. Trying to match word for word the translation from English to Spanish will create more confusion.

Instead, it’s best to pay attention to the way native speakers talk. You can learn the sentences they use and start imitating them. The translation doesn’t have to make sense, sometimes it won’t make sense at all!

If any of this is confusing, it’s okay. That’s a completely normal part of the process of learning a new language. So you’re not alone! All learners go through this. And like anyone else, you’ll be able to overcome the obstacle and master the language!

Just remember, accidental “se” constructions might seem a little weird at first. But, if you focus on the right formula, learning complete sentences, and shifting your perspective to passive meaning… You’ll succeed!

You can start using these sentences today and notice how your Spanish will sound more natural and flow more easily. Have fun with it!