Vida Inglés

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Lecciones de Inglés

have to, must (obligación)

Gramatica:

Utiliza must / have to para decir que algo es obligatorio, importante o urgente. Le sigue un verbo en infinitivo. El verbo have to significa lo mismo que must en oraciones positivas. En oraciones negativas tiene un significado diferente. Must se usa en oraciones positivas o negativas pero no en interrogativas o respuestas.

must positivo

Must es un verbo modal. No lleva "s" al final cuando el sujeto es he, she, it.

Positivo:

  • I must be on time.
    ( Debo ser puntual.)
  • She must be on time.
    (Ella debe ser puntual.)
  • You must stop at the red light.
  • They must study before the test.

have to positivo

Usa have to para expresar obligaciones, reglas o costumbres. Usa has to para referirnos a terceras personas singular. Usa have to para el presente, had to para el pasado y will have to para el futuro.

  • You have to drive on the left in Scotland.
  • She has to wash her hair every day.
  • Yasuni had to wash the car yesterday.
  • In the future, we will have to stop eating processed food.

Forma interrogaciones con el verbo have to en lugar de must.

Estructura:

  • Do/Does + sujeto + have to + verbo en infinitivo
  • Do I have to stay home?
    Yes, you do. NO: Yes, you have to.
  • Does he have to go with you?
    Yes, he does. NO: Yes, he has to.
    No, he doesn't. NO: No, he hasn't.

mustn't negativo

musn't significa que esta prohibido y no permitido hacer:

must not = musn't
  • You mustn't drive on the left side of the road.
  • She mustn't go out with him.
  • They mustn't talk during class. (No deben hablar durante la clase.)

don't have to negativo

Do not have to significa que no es necesario.

  • They mustn't read the newspaper. (Prohibido)
  • They don't have to read the newspaper. (No es necesario.)

Para hacer preguntas es mas usual usar have to que must:

  • Do I have to stay after class? NO Must I stay after class?
  • Yes, you do. NO: Yes, you have to.

En oraciones positivas usa must o have to. Tienen el mismo significado.

  • They have to/must cook something for lunch.

En oraciones negativas, have to y must tienen significados completamente diferentes: don't have to significa que no es necesario hacerlo, mustn't significa que es obligación o está prohibido hacerlo.

  • You mustn't eat here = (esta prohibido o no permitido)
  • You don't have to eat here = (no es necesario)

Actualizado: 2017-01-18 09:20:08

No hay ejercicio de have to, must (obligación) por el momento.