Ingles

All modal perfect auxiliary verbs refer to the past.
FORM: Modal + Have (Infinitive) + Past Participle

1. must have done = we are almost sure something happened in the past

Jane wasn't feeling well yesterday. She must have caught a cold.
Bill didn't answer the phone when I called him. He must have fallen asleep.

2. can't have done = we are almost sure something did not happenin the past

She can't have forgotten to send you an invitation. I gave her your address.
They can't have gone to bed late. They were very tired.

3. may / might / could have done = it is possible that something happened in the past but we aren't sure.

Laura hasn't arrived yet. She may/might/could have missed the bus.
I didn't see Paul at work. He may/might/could have beenill.

4. could have done = we had the ability to do something in the past but did not do it.

You could have told us about the new project!
She could have called me when she arrived but she forgot.

5. should have / ought to have done = (a) it was the right thing to do but we didn't do it. (b) we expected something to happen but it didn't.

You should have told him the truth.They ought to have received the cheque by now.

6. would have done = we wanted to do something but we didn't do it in the end.

They would have emailed you but the Internet was down yesterday.
I would have bought that DVD but I didn't have enough money.

7. needn't have done = it wasn't necessary to do something but we did it.

You needn't have gone to the supermarket.I've already done the shopping.
The weather was warm and sunny. I needn't have taken an umbrella.
Todos los verbos auxiliares modales perfectos refieren al pasado.
FORMA: Modal + Have (infinitivo) + Participio Pasado

1. debe haber hecho algo = estamos casi seguros que sucedió en el pasado

Jane no se encontraba bien ayer. Debe de haber cogido un resfriado.
Bill no contestó elteléfono cuando lo llamé. Debe de haber dormido.

2. no pueden haber hecho = estamos casi seguros de que algo no sucedió en el pasado

No puede haber olvidado de enviarle una invitación. Le di su dirección.
No pueden haber ido a la cama tarde. Estaban muy cansados.

3. puede / podría / podríamos haber hecho = es posible que algo que sucedió en el pasado, pero no estamos seguros.Laura no ha llegado todavía. Ella puede / podría / podríamos haber perdido el autobús.
No vi a Paul en el trabajo. Él puede / podría / puede haber estado enfermo.

4. podría haber hecho = teníamos la capacidad de hacer algo en el pasado, pero no lo hizo.

Usted podría haber nos dijo sobre el nuevo proyecto!
Podía haberme llamado cuando llegó, pero se olvidó ella.

5.debería tener / debería haber hecho = (a) que era lo correcto, pero no lo hizo. (B) se espera que pase algo, pero no lo hizo.

Deberías haberle dicho la verdad.
Ellos deberían haber recibido el cheque por ahora.

6. habría hecho = queríamos hacer algo pero no lo hizo al final.

Te habrían enviado por correo electrónico, pero el Internet no funcionó ayer.
Me hubiera compradoese DVD, pero no tenía suficiente dinero.

7. no tiene por qué haber hecho = no era necesario hacer algo, pero lo hicimos.

Usted no tiene por qué haber ido al supermercado. Ya he hecho las compras.
El tiempo era cálido y soleado. Tengo que no han tomado una sombrilla.

First Conditional: real possibility

We are talking about the future. We are thinking about a particularcondition or situation in the future, and the result of this condition. There is a real possibility that this condition will happen. For example, it is morning. You are at home. You plan to play tennis this afternoon. But there are some clouds in the sky. Imagine that it rains. What will you do?
IF condition result
present simple WILL + base verb
If it rains I will stay at home.

Notice that we...