So do I, neither do I: agreeing in short

When you use it

When someone tells you something about themselves and it is true for you too, English has a very short way to say so. After a positive sentence you reply with so: I love winter. — So do I. After a negative sentence you reply with neither: I didn't hear the alarm. — Neither did I. These replies are everywhere in conversation. The same pattern can also join two halves of one sentence: Tom enjoys camping, and so does Anna. In relaxed speech many people simply say Me too or Me neither.

How it is formed

The reply has three parts: so or neither, a helper verb, and the subject. For agreeing, the helper verb comes before the subject: So do I, Neither can Tom.

You do not choose the helper verb freely. Look at the verb in the first sentence and copy its type (you will use the same idea later in question tags):

An ordinary verb has no helper of its own, so the reply brings in do, does or did, just as a question or a negative does (see present simple questions and negatives). When have is the main verb (I have a bike), it is an ordinary verb too, and the usual reply is So do I. With have got the helper is have: I've got a bike. — So have I.

A few more points.

• The helper verb matches its own subject, not the first speaker's: I play tennis. — So does Anna. / Anna plays tennis. — So do I.
• Neither is already negative, so the helper after it is positive: Neither do I, not Neither don't I.
• Nor means the same as neither and works the same way: Nor do I. It is a little more common in British English.
• Never also makes a sentence negative: Tom never takes the bus. — Neither do I.
• In speech the stress falls on the last word: so do I, neither can Tom.

Me too and me neither. Me too answers a positive sentence and Me neither a negative one. They are very common in everyday speech and perfectly correct, but they do not show the verb, and they only talk about you. (Some American speakers also say Me either in the same way.) As a reply on its own, I too sounds formal or old-fashioned, so in conversation say Me too or So do I.

When it is not true for you. Then you reply with the subject and the opposite form of the helper verb, often after Really? or Oh: I hate spiders. — Really? I don't. / I'm not ready. — Oh, I am. / I can't ski. — I can. A positive reply like I am or I have keeps the full form at the end, never I'm or I've.

Examples

• I love winter. — So do I.
• Anna is nervous about the exam. — So am I.
• Tom can't read music. — Neither can I.
• I didn't hear the alarm. — Neither did I.
• I've finished my homework. — So has Tom.
• I was bored at the party. — So was I.
• I won't forget this day. — Nor will I.
• Tom enjoys camping, and so does Anna.
• I don't understand this word. — Me neither.
• I hate spiders. — Really? I don't.

Common mistakes

• ✗I speak a little French. — So am I.

  ✓ I speak a little French. — So do I.

  Speak is an ordinary verb in the present, so the reply needs do. So am I would only fit after a sentence with a form of be, such as I'm cold or Anna is cold. Я теж has no verb in it, so Ukrainian gives no clue. The clue is the verb in the other person's sentence. Я тоже has no verb in it, so Russian gives no clue. The clue is the verb in the other person's sentence. Ich auch works after every tense and every verb. English has to choose: am, do, did, have, can and so on.

• ✗I don't drink milk. — Neither don't I.

  ✓ I don't drink milk. — Neither do I.

  Neither already carries the meaning of not. Standard English uses only one negative word here, so the helper verb after neither stays positive. Я теж не п'ю keeps не, so a second negative word feels natural. Я тоже не пью keeps не, so a second negative word feels natural. Ich auch nicht puts nicht in the reply. In English neither is the nicht part, so nothing else is negative.

• ✗I'm thirsty. — So I am.

  ✓ I'm thirsty. — So am I.

  For agreeing, the verb comes before the subject. So I am with the subject first does exist, but it says something different: you notice that something is true, as in Your shoes are wet. — Oh, so they are. In Я теж the subject comes first, so I wants to come first in English too. In Я тоже the subject comes first, so I wants to come first in English too. German also puts the verb before the subject after a word at the front (Heute bin ich müde), so So am I follows a pattern you know.

• ✗I can't open this window. — Me too.

  ✓ I can't open this window. — Me neither. / Neither can I.

  Me too agrees with a positive sentence. After a negative sentence, use Me neither or Neither + helper verb + subject. Я теж can also answer a negative sentence, so Me too seems to fit both. Я тоже can also answer a negative sentence, so Me too seems to fit both. German makes the same split, Ich auch and Ich auch nicht, so Me too and Me neither map onto them directly.

• ✗Anna lives near the park. — So does I.

  ✓ Anna lives near the park. — So do I.

  The reply copies the type of verb, not its exact form. Lives has its -s because of Anna. The new subject is I, and I takes do.

Practice

The exercises go from easy to harder. Each answer is checked at once. If it is wrong, you get a hint and a second try.