In Spanish, there are two important words that mean "to be": "ser" and "estar."

Knowing how to use each one is very important, especially when talking about things that happened in the past.

1. Using "ser":

• What it means: We use "ser" to show who did something.
• Example: "El libro fue escrito por el autor."
  (This means: The book was written by the author.)

2. Using "estar":

• What it means: We use "estar" to show the result of an action. It often describes a temporary state.
• Example: "El libro está terminado."
  (This means: The book is finished.)

3. When to use each one:

• Use "ser" when you want to focus on the action and the person who did it.
• Use "estar" when you want to talk about how something is right now.

By knowing when to use "ser" and "estar," you can express yourself better in Spanish!