Short answers, so do I, neither do I, and I think so

What a short answer leaves understood

A short answer keeps enough words for the listener to understand the rest. In Are the windows open? Yes, they are, the words open and the windows do not need repeating in full. They stands for the windows; are carries the verb form.

A helper verb works with another verb: is reading, has finished, didn't stop. A modal is a verb such as can, will or should. In a matching short answer, keep the first helper or modal from the question. With be as the main verb, keep be itself.

This is a matching pattern, not a rule that every sensible reply must repeat the question's verb. You can give a different answer or change your level of certainty. You will see that contrast below.

Use do, does or did for ordinary present and past verbs

A present simple or past simple yes/no question with an ordinary main verb uses do, does or did. Keep that helper in the short answer. Do not put the main verb after it unless you want to say the full clause.

Do not use do merely because the question asks about an action. Can you repair it? has can, so its matching answer is Yes, I can. Are you repairing it? has are, so you answer Yes, I am when speaking about yourself.

Main-verb have and helper have need attention: Do you have a ticket? Yes, I do; Have you got a ticket? Yes, I have; Have you printed the ticket? Yes, I have. Follow the actual question form rather than choosing one answer for every meaning of possession.

Match the person and the first helper

You may need to change the subject when you answer. If someone asks you about yourself with you, your answer uses I. The verb must agree with that new subject: Are you comfortable? Yes, I am, not a mechanical copy of are.

In have been checked, the first helper is have. In will have finished, it is will. A matching answer does not take a later helper just because it is closer to the main verb.

With we, think about the group. If you are part of the group asked about, Yes, we are may fit. If you are outside that group, Yes, you are may fit. Short answers still refer to real people; their pronouns are not an automatic word-swap exercise.

Full positive endings and negative contractions

A contraction joins words in a shorter form, such as I'm for I am. Do not end an ordinary positive short answer with a subject-plus-helper contraction. Say Yes, I am, Yes, she has or Yes, we will, with the final verb written in full.

Negative contractions such as isn't, haven't and won't can stand at the end. In No, I'm not, I'm is not the last word: not follows it. A positive contraction is also fine when more of the clause follows, as in Yes, she's waiting. The problem is the shortened ending Yes, she's on its own, not every use of she's after yes.

Answer the fact, including after a negative question

In the usual short-answer pattern, yes goes with a positive answer and no with a negative one. Decide what is true. Do not decide only from the presence of not in the question.

• A: Haven't you sent the form? B: Yes, I have. I sent it before lunch. The form has been sent.
• A: Isn't the shop open? B: No, it isn't. It opens at ten. The shop is not open.

These examples give the usual factual answer. Real conversations can use yes and no to react to different parts of a discussion. Add a full sentence if a bare answer could be misunderstood. See Negative questions: isn't it, why don't you, didn't you for the meanings and tone of negative questions.

You can change the reply's meaning

A matching answer keeps the question's helper and meaning. A different modal can change the message. If someone asks Will you join us?, I might says that joining is possible, not certain. It is not the same promise as I will.

• A: Will you help at the event? B: I might. I need to check my timetable. A possible action, not a firm commitment.
• A: Can you come on Friday? B: I can't, but I could come on Saturday. The speaker gives a different possibility.

In longer shortened replies, more than one helper may be needed. Did you send a reminder? No, but I should have leaves sent a reminder understood. Should have keeps the past meaning. Do not apply the beginner matching pattern as a ban on every longer reply.

Agreeing or disagreeing about the same fact

You can use short answers after a statement as well as a question. Here you confirm or reject the same fact, rather than adding a second person with the same experience.

With a negative statement, No, I haven't can agree with its negative meaning. Yes, I have corrects it. Agreement does not always mean saying yes.

For a different personal experience, use the appropriate positive or negative short clause. I enjoy long journeys. I don't gives two contrasting opinions. I can't stay late. I can contrasts two people's ability or availability. The helper and subject show whose experience is being added.

So do I: adding the same positive experience

Its form is short, but it combines subject choice, verb choice and changed word order. So here means too or as well. You add another person or group for whom a positive statement is true.

Put the helper before the new subject. This changed order is called inversion. Match the verb to the new subject: I am tired. So is my sister. You keep the kind of verb, not always its exact form. With an ordinary present or past simple verb, use do, does or did.

You can join the addition to a longer sentence: Nora takes the bus, and so do her neighbours. The neighbours are an added subject. Do not confuse this so with so meaning a result in The bus was late, so we walked.

Neither and nor: adding the same negative experience

Use neither or nor plus a positive helper before the subject to mean also not. The negative meaning is already in neither or nor; do not add another not to this pattern.

Negative meaning can come from words other than not. After I never work on Sundays, Neither do I adds the same negative habit. After I hardly know the area, Nor do I says that you also know very little about it. With sometimes, the statement is positive: I sometimes work on Sundays. So do I.

Do not confuse this response pattern with neither... nor linking alternatives, as in neither tea nor coffee. The response Neither do I does not need a second nor phrase. See Both, either and neither: both doors, either of them, neither answer for other uses.

Other ways to add the same experience

You can keep statement word order with too in a positive addition, or not... either in a negative one. These give alternatives to the inverted patterns.

Me too and Me neither refer to the person speaking. Use a full pattern if you want to add somebody else: So does my father or Neither does my father. A negative reply with either keeps a negative verb: I don't either, not I do either for this meaning.

So I do: recognising the same fact

So do I and so I do do not have the same word order or the same job. In so do I, you add yourself as another person with the same experience. In so I do, you recognise or confirm a fact about yourself that someone has pointed out.

This second pattern keeps subject-before-verb order. Do not cross it out as a grammar error simply because you have learned so + helper + subject. Decide whether you mean an additional experience or recognition of the original fact.

I think so and I hope not

After verbs such as think, believe, expect, suppose and hope, so can stand for a whole idea. It does not stand for a noun like the book. Will the library be open? I think so means I think the library will be open.

Hope is not the same as certainty. Will the parcel arrive today? I hope so expresses what you want; it does not promise that the parcel will arrive. Choose the verb for your meaning, not simply because every reply contains so.

The negative pattern depends on the verb. In ordinary use, choose I don't think so, I don't believe so or I don't expect so. With hope and be afraid, use not after the verb: I hope not; I'm afraid not. I suppose not and I don't suppose so are both possible.

• A: Will there be another delay? B: I hope not. We have already waited an hour. The speaker wants there to be no further delay.
• A: Is the office open on a holiday? B: I don't think so. We should check. The speaker thinks it is probably not open.
• A: Can I leave my bag here? B: I'm afraid not. This doorway must stay clear. A negative answer presented with regret.

Cambridge records I think not, I believe not and I expect not in classic literature or very formal situations. They are not simple grammar errors. The ordinary reply pattern here is I don't think so and its equivalents.

Choose either the short substitute or the full clause: I think so or I think the train stops here. Do not combine them as I think so the train stops here. In the ordinary complete short reply, include so: Yes, I think so, not just Yes, I think.

Probability words, fragments and short questions

You can answer with a word or phrase that shows how certain you are: perhaps, maybe, probably, definitely. A negative reply can put not after the probability word: probably not or maybe not. The meaning must still fit the question.

• A: Will you need a larger table? B: Probably. The speaker thinks a larger table is likely to be needed.
• A: Are the extra chairs necessary? B: Probably not. The speaker thinks they are unlikely to be needed.

You can also give just the information requested: Which platform? Platform four; Who has the key? Lena. A yes/no helper answer would not supply that missing detail. Words can be left out when the conversation makes their meaning clear. This is called ellipsis.

A short question is different from an answer: A: The train has been cancelled. B: Has it? asks about or reacts to the news. Yes, it has confirms it. What time? asks for a detail. See Echo and reply questions: checking what you heard for these reply and echo questions.

An agreement tag adds another short question to your reply, as in Yes, it is, isn't it?. See Question tags: isn't it? don't you? for tag formation. Neither a tag nor an echo question replaces the answer patterns above.

What comes next

Use Question forms: yes/no and wh- questions for full question formation, Negative questions: isn't it, why don't you, didn't you for negative questions and their answers, Question tags: isn't it? don't you? for attached tags, and Echo and reply questions: checking what you heard for reply and echo questions. Use Both, either and neither: both doors, either of them, neither answer for other uses of either and neither.