Tag Questions

"Tag questions" son preguntas que se usan para confirmar lo que piensas que es verdad.

You Speak Spanish, don't you?

(Con esta pregunta indico que pienso que hablas español pero quiero confirmar que asi es:)

Para formar un Tag Question empiezas con la oración que piensas que es verdad ("You Speak Spanish" en el ejemplo de arriba). El Tag ( la parte de la oración que hace que sea una pregunta) se forma usando un verbo auxiliar en el negativo si la oración fue afirmativa o un un vervo auxiliar en el afirmativo si la oración fue afirmativa.

Oraciones Afirmativas  (El verbo auxiliar en el "tag" es negativo.)	Oraciones Negativas  (El verbo auxiliar en el "tag" es afirmativo.)
to be
You're a teacher, aren't you?	You aren't a teacher, are you?
He's tired, isn't he?	He isn't tired, is he?
Tiempo Presente
You speak English, don't you?	You don't speak English, do you?
He swims, doesn't he?	He doesn't swim, does he?
Tiempo Pasado
He went to school, didn't he?	He didn't go to school, did he?
Presente Perfecto
You have finished, haven't you?	You haven't finished, have you?
He has left, hasn't he?	He hasn't left, has he?
Futuro
She will cook, won't she?	She won't cook, will she?

*El único que no sigue el patrón arriba es la forma afirmativa de "am". El negativo, sin embargo, sigue el patrón. Ve los ejemplos abajo.

I'm tall, aren't I?
I'm not tall, am I?

                               

Práctica
Selecciona el "tag" correcto para cada oración.

1. They are students,  
2. She is a teacher, 
3. We are ready 
4. He isn't from China, 
5. They aren't tall,  
6. I'm not on the list,  
7. I'm the winner,  
8. She sings beautifully,  
9. They live in France, 
10. He doesn't like movies, 
11. You don't cook well, 
12. They moved, 
13. She didn't leave, 
14. You saw the show, 
15. He has finished,  
16. They haven't read the book,  
17. You've gone there, 
18. She hasn't written the article, 
19. You will go to the party,  
20. They won't see her, 

Modals – deduction : must, can't, might/may/ould

We use modal verbs to say how sure we are about something.

1 must

We use must when we feel sure that something is true because there’s very strong evidence.

• He must live near here because he comes to work on foot. We don’t know where he lives but we’re sure it’s not far away.
• Come inside and get warm – you must be freezing out there.
• You’re a zookeeper? That must be very interesting.

Notice that must is followed by an infinitive without ‘to’.

2 might, may, could

We use might, may or could to say that we think something is possible but we’re not sure.

• Did you hear that? I think there might be a burglar downstairs. She’s not sure there’s a burglar but she thinks it’s possible.
• We’ll try to get there early but we may arrive late if there’s a lot of traffic.
• Don’t put it up there. It could fall off and hit someone.

Might, may and could are also followed by an infinitive without ‘to’.

3 can’t

We use can’t when we feel sure something is not true.

• It can’t be a burglar. All the doors and windows are locked. He doesn’t know it’s not a burglar but he feels sure it’s not.
• It can’t be far away now. We’ve been driving for hours. Where’s the map?
• Really? He has to work on Christmas Day? He can’t feel very happy about that.

Like the other verbs, can’t is followed by an infinitive without ‘to’.

Remember that all of these modal verbs – must,might, may, could and can’t have other uses. These are covered in another section.

CERTAINTY ABOUT THE PRESENT

When making deductions about the present, we use must if we are sure something is true and can’t if we are sure that something is impossible.

“He must be a chef.”

For example, if you see this guy, you can say:

• He must be a chef.
  (we are very certain, because of his uniform and what he is doing)
• He can’t be a policeman.
  (we are very certain he is NOT a policeman)

Carla works every day from 9 AM to 5 PM. Right now it’s 10:30 AM, so…

• She must be at work.
• She can’t be at home.

CERTAINTY ABOUT THE PAST

When we consider some present evidence and draw a reasonably certain conclusion about what happened in the past, we use must have and couldn’t have plus the past participle of the verb.

must have + past participlewhen we draw the conclusion that something DID happen

• Sheila got a tan. She must have spent a lot of time in the sun lately.
• There was one banana left, but now it’s gone. My husband must have eaten 

must not have + past participlewhen we draw the conclusion that something did NOT happen

• The car is still dirty. Paul must not have washed it yet.
• He barely touched his lunch. He must not have been

couldn’t have + past participlewhen we are certain that something was IMPOSSIBLE

• Martha couldn’t have takenyour notebook; she wasn’t even in class yesterday.
• The cookies are gone. But Eric couldn’t have reached the cookies on the top shelf; he must have asked his older brother to get them.

Can’t have is also possible, but it is much less common than couldn’t have.

Here’s an example that illustrates the difference between must not have and couldn’t have:

• I don’t see the report here – she must not have printed it out.
  (we draw the conclusion that she did not do it)
• The printer’s been broken for the past week, so she couldn’t have printed out the report.
  (we know it was IMPOSSIBLE for her to do it)

CERTAINTY ABOUT THE FUTURE

Making deductions about the future is the same as making predictions. As you learned in the lesson about future tenses, we can use will or going to for saying what we believe will happen in the future. When you are quite sure that your prediction is correct, you can also add the word definitely to emphasize your certainty:

• She‘s definitely going to love this book – it’s by her favorite author.
• The kids will definitely be thrilled when we tell them we’re going to Disney World.

Two slightly more formal expressions that can be used for talking about the future with certainty is saying that something is certain to happen, or is sure to happen:

• Engineers are certain to develop even faster computers.
• The country is sure to come to the aid of its ally.

Modal Verbs For Expectation

PRESENT/FUTURE EXPECTATION

When you expect something to happen (although you are not completely, 100% certain), you can use should/shouldn’t for the present or future:

• Present:I took my car to the mechanic yesterday and he said the problem would be fixed in a day – so my car should be ready by now.
• Future:Can you please type up these notes? It should only take about half an hour.
• Present:The weather is clear, so our flight shouldn’t be delayed.
• Future:I’ve written out all the instructions for this task step by step, so you shouldn’t run into any problems when you try to do it.

PUT IT INTO PRACTICE!

What is one thing you expect to do or one thing you expect to happen within the next week? Create your own sentence using should:

Ex) Within the next week, I should finish the book I’m reading.

PAST EXPECTATION

For expectations about what was supposed to happen in the past, you can use should have and shouldn’t have plus the past participle:

• I sent the package three weeks ago with express mail. They should have received it already.
  = I expect that they have already received it
• This car is brand new. It shouldn’t have broken down.
  = I expected it NOT to break down

Because should/shouldn’t are also used for giving advice and recommendations, we can also use should have and shouldn’t have for evaluating things in the past and declaring them to have been right or wrong, good or bad:

• Lindsay saw a woman who needed help, but did nothing.
  “Lindsay, you should have helped her.”
• I said something mean to my best friend during an argument.
  “I shouldn’t have said that. It really hurt her feelings.”

PUT IT INTO PRACTICE!

Think of one thing you regret doing, and one thing you regret NOT doing. Make sentences about them using should/shouldn’t have + the past participle:

• I should have…
• I shouldn’t have…

Modal Verbs For Possibility

PRESENT/FUTURE POSSIBILITY

We can use may, might and could to talk about things that are possible in the present and future.

Present: 

• Where’s Fred? He’s not in his office.
  He maybe in the bathroom… or he might be in the conference room.
• Don’t eat that mushroom. It could be poisonous.

Future:

• The weather forecast says it may rain tomorrow.
• Your daughter is really smart. She could be very successful someday.
• We might take a road trip this weekend.

Some people say that might is less certain than may, but in spoken English there is really no effective difference. It’s probably best to use might. The word may is less common, and we can only use could in the positive form, not the negative form, for talking about possibility:

• Are you sure that’s a good idea?
  The boss may not / might not like it when he finds out.
  The boss could not like it when he finds out.
• I may not /might not be the smartest person in the class, but I definitely work the hardest.
  I could not be the smartest person in the class, but I definitely work the hardest.

PAST POSSIBILITY

When talking about past possibilities, we can use… might have / may have / could have + past participle (for positive possibilities) and might not have / may not have + past participle (for negative possibilities).

Positive Past Possibilities:

• She’s not home. She might have gone to the store.
• He may have misunderstood you when you talked to him yesterday.
• The person who stole the documents could have been one of the employees.

Could have is usually used in unreal conditions – when we are imagining a possibility if something in the past had been different: “If we had started this project earlier, we could have finished on time.”

Negative Past Possibilities:

• John’s not here. He might not have known about the meeting.
• If she hasn’t called you back, she may not have listened to your voicemail yet.

Remember that couldn’t have is only used when we are certain that something is logically impossible in the past:

• She couldn’t have taken the car; she doesn’t have a key.

Summary

• Use must (present) and must have (past) when you are very certain that something is/was true
• Use can’t (present) and couldn’t have (past) when you are very certain that something is/was impossible
• Use should/shouldn’t (present) and should have / shouldn’t have (past) to talk about things you expect to be true, although you don’t have complete certainty
• You can also use should have / shouldn’t have for judging actions in the past to be good or bad
• Use might (most common), may, or could to talk about present and future possibilities
• Use might have, may have, or could have to talk about past possibilities
• For a possibility that something did NOT happen, use might not have and may not have