¿Qué es?
Can, can’t, could y couldn’t son verbos modales.
Se usan para hablar de:
- habilidad presente
- habilidad pasada
- permiso
- peticiones
- posibilidad
Can es la forma positiva.
- I can swim.
Can’t es la forma corta de cannot.
- I can’t drive.
Could se usa a menudo para habilidad pasada o peticiones corteses.
- She could read when she was four.
- Could you help me?
Couldn’t es la forma corta de could not.
- We couldn’t find the address.
Cuándo usar
Usa can para habilidad presente.
- He can speak English.
- I can cook.
Usa can’t cuando alguien no es capaz de hacer algo.
- She can’t swim.
- We can’t come today.
Usa can para pedir o dar permiso.
- Can I use your phone?
- You can leave early.
Usa could para habilidad general en el pasado.
- I could run fast when I was younger.
- They could speak French as children.
Usa couldn’t para falta de habilidad o una situación no exitosa en el pasado.
- He couldn’t read the sign.
- We couldn’t open the door.
Usa can o could para hacer peticiones.
- Can you close the window?
- Could you close the window?
Could suele ser más cortés que can en las peticiones.
Estructura
Usa la forma base del verbo después de can, can’t, could y couldn’t.
| Forma | Estructura | Ejemplo |
|---|---|---|
| Presente positivo | sujeto + can + verbo base | She can drive. |
| Presente negativo | sujeto + can’t + verbo base | She can’t drive. |
| Pasado positivo | sujeto + could + verbo base | She could drive at eighteen. |
| Pasado negativo | sujeto + couldn’t + verbo base | She couldn’t drive last year. |
La forma es la misma para todos los sujetos.
- I can swim.
- He can swim.
- They can swim.
No agregues -s después de he, she o it.
Preguntas
Usa:
Can/Could + sujeto + verbo base?
| Tipo de pregunta | Ejemplo |
|---|---|
| Habilidad presente | Can you swim? |
| Permiso | Can I sit here? |
| Petición | Can you help me? |
| Petición cortés | Could you help me? |
| Habilidad pasada | Could she read at five? |
Respuestas cortas
- Can you drive? — Yes, I can.
- Can he come? — No, he can’t.
- Could they swim? — Yes, they could.
- Could she open it? — No, she couldn’t.
Ejemplos
- I can speak a little Spanish.
- She can’t come to work today.
- Can you help me with this box?
- Can I open the window?
- You can use my computer.
- He could swim when he was five.
- We couldn’t find a taxi last night.
- Could you speak more slowly, please?
- They could not hear the announcement.
- My brother can cook very well.
Excepciones
Usa could para habilidad general en el pasado.
- She could play the piano when she was young.
Para una acción específica exitosa en el pasado, was able to suele ser más natural.
- We were able to fix the problem yesterday.
Sin embargo, couldn’t es natural para una acción específica no exitosa.
- We couldn’t fix the problem yesterday.
Cannot se escribe como una sola palabra.
- Correcto: cannot
- Incorrecto: can not
La forma can not es posible solo cuando not pertenece a otra frase, pero este uso es poco común.
Errores comunes
-
Incorrecto: She cans swim. Correcto: She can swim. Explicación: No agregues -s a los verbos modales.
-
Incorrecto: I can to drive. Correcto: I can drive. Explicación: Usa el verbo base sin to después de can.
-
Incorrecto: He could speaks English. Correcto: He could speak English. Explicación: Usa la forma base después de could.
-
Incorrecto: Do you can help me? Correcto: Can you help me? Explicación: No uses do en preguntas con can.
-
Incorrecto: I don’t can swim. Correcto: I can’t swim. Explicación: Usa can’t, no don’t can.
-
Incorrecto: She could to read at four. Correcto: She could read at four. Explicación: No uses to después de could.
-
Incorrecto: Can you helped me? Correcto: Can you help me? Explicación: Usa la forma base del verbo después de can.
-
Incorrecto: I couldn’t found my keys. Correcto: I couldn’t find my keys. Explicación: Usa la forma base después de couldn’t.