Verbos Modales

presente-futuro | pasado

Forma

Los verbos modales o auxiliares (can, must, should, may, etc.) siempre van seguidos del infinitivo de otro verbo SIN TO: I must go
No añaden -s a las tercera persona del singular de presente (siempre aparecen en su forma base): She can drive
Las preguntas se forman invirtiendo el orden de las palabras: auxiliar + sujeto + infinitivo: May I come in?
La forma negativa se forma añadiéndoles NOT (N'T): I can't understand / You shouldn't swear

Verbos Modales (presente-futuro)

Usos

CAN

Habilidad (saber): I can drive. She can't swim. Can you ski?

Posibilidad o no posibilidad: I can't come.When can you start work?I can meet you at nine

Para pedir permiso (forma coloquial) You can come in now. Can I use your phone?. You can't smoke here

Para pedir permiso (no formal): Can you help me? Can you carry this suitcase?

COULD

Habilidad general de pasado (sab\'eda): I could read when I was three. My parents couldn't speak English

Posibilidad: It could be true -Solicitar algo (formal): Could you post this letter for me? Could you shut the door, please?

Sugerencias, consejos: You could go to bed early. We could go for a walk

WILL/SHALL se usan para

Hacer predicciones de futuro: You'll be famous. There will be a new ice age

Hacer ofrecimientos: I'll carry that for you. Shall I pay for it?

Hacer solicitudes(=can): Will you pass the salt please? Will you shut the window please?

WOULD

Hacer ofrecimientos / invitaciones: Would you like a drink? Would you like to como to a party?

Para pedir algo: Would you give me a lift? Would you carry this for me?

Para hablar de hábitos de pasado (=used to): When I was young, Y would go out every night

SHOULD / OUGHT TO

Hablar de obligaciones - deberes: You should tell the police. You shouldn't smoke here

Dar consejo: You should go to bed, you look tired. You oughtn't to worry so much

Hacer predicciones: They should be here soon. He should win the match easily

Para hacer sugerencias: You should/ought to see that film

MUST

Obligación / prohibición: You must pay for the damage. You mustn't drive so fast

Necesidad: I must go now. We must get up early tomorrow

Certeza en las predicciones: Look at their house -they must be rich. She's crying -she must be unhappy

CAN'T

Forma negativa de MUST cuando indica predicción cierta: She can't be a student, she looks older

HAVE TO

Obligación / deber: She has to wear a uniform. I have to write three essays a week. I don't have to make my bed

Necesidad pasada o futura: We had to walk home. You'll have to buy some new clothes

MAY/MIGHT

Posibilidad-probabilidad futura:It may/might break. He may/might not pass the exam

Solicitudes cortesas: May I come in? May we go now?

Para dar permiso: You may smoke if you want to. You may not leave without permission

NEEDN'T

Falta de necesidad, no tener que (=don't have to): You needn't shout, I can hear you

Verbos Modales (pasado)

Modal + have + past participle

Forma

Los verbos modales estudiados anteriormente se refieren al presente o futuro. La mayoría de estos verbos pueden ir acompañados de HAVE + PARTICIPLE para referirnos al pasado

They must have left (=han debido irse)

MIGHT / MAY / COULD HAVE:

para hablar de posibilidades de pasado: I've lost my passport. Somebody could have stolen it / It's not very late. They may not have gone to bed

MUST HAVE:

deducciones o certeza en el pasado: They're late. They must have missed the bus / He's not here. He must have gone

CAN'T HAVE:

para imposibilidades de pasado: It's early. They can't have gone to bed / The exam was easy. She can't have failed it

SHOULD / SHOULDN'T HAVE:

Para lamentarse de errores del pasado: We should have left earlier / I shouldn't have driven so fast

NEEDN'T HAVE:

para falta de necesidad del pasado: He's OK. We needn't have worried / You needn't have run, you're not late

Date cuenta de la diferencia entre needn't have y didn't need to: He needn't have done it / He didn't need to do it