Jerónimo's Lesson

Modal verbs: must, should and have to.

Must

• Modal verb of obligation.
• The speaker thinks it is necessary.
• La obligación es PERSONAL. Obligaciones externas en contextos formales (la ley o las reglas).
• Negative: prohibition. Cuando NO es necesario ejecutar una acción.

He musn't call her at work.

S + MV + V. infinitive + C

You musn't wait here.

I must finish this work before Friday.

Passengers must show their identification to the authorities.

Have to

• Modal verb of obligation.
• External obligation: cuando para alguien externo es una obligación.
• No obligation: you can do something but you don't need to do it.
• Give an advice.

You have to cut down on sugar.

S + MV + V. infinitive + C.

I have to pay the bills every month.

We don’t have to wear suit and tie on Fridays.

You have to tell the police what you saw.

She has to clean the house before they arrive.

Should

• Modal verb of obligation.
• Giving advice: to say what is or isn’t the right thing to do.
• When something is possible (probable).
• Para mostrar obligación o dar una opinión.

You should stop eating fast food.

Should we turn left at this street?

We should go to the park tomorrow.

• I think you should buy a new pair of shoes for the party.

He should be bringing Jennifer with him.