Guide to English grammar

43 Patterns with so, neither etc

1 Too, either, so and neither/nor
1 After a clause there can be a short addition with too or either. The positive pattern is “subject + auxiliary + too”. The negative is “subject + auxiliary + n't+ either”.
You're cheating. -You are, too.
Barbara can't drive, and her husband can't either.
In simple tenses we use the auxiliary verb do.
I like chocolate. -I do, too.
That torch doesn't work. -This one doesn't either.
We can also use be on its own as an ordinary verb.
I'm tired. -I am, too.

2 An addition to a positive statement can also have this pattern with so.

I like chocolate.-So do I.
You're beautiful. -So are you.
Children should behave themselves, and so should adults.
So here means the same as too. There is inversion.
NOT I like chocolate. -So I do.

For So I do, • (4).

3 An addition to a negative statement can also have this pattern with neither or nor.
Barbara can't drive, and neither/nor can her husband.
We haven't got a dishwasher. -Neither/Nor have we.
The ham didn't taste very nice. -Neither/Nor did the eggs.
Neither and nor mean the same as not... either.
A practical guide to English grammar 41
NOTE

1. 
   There is no difference in meaning between neither and nor, but nor is a little more formal.
   
2. 
   The first sound in either/neither is /i:/ in the USA and usually /ai/ in Britain.
   

4 In these examples a negative addition follows a positive statement, and vice versa.

I'm hungry now. -Well, I'm not.
We haven't got a dishwasher. -We have.

2 Do so, do it and do that
“Do so” and “do it” refer to an action which is clear from the context. Do so is a little formal.
Anna had often thought of murdering her husband, but she hesitated to actually do so/do it.
I wanted to jump, but I just couldn't do it.
Here the stress is on do, not on so/it. We are interested in whether or not someone does the action.
When “do that” refers to an action, the stress is usually on that.
I might murder my husband. -Oh, I wouldn't do that if I were you.
Here we are interested in or surprised at what kind of action it is.

3 So and not replacing a clause

1 So can stand for a whole clause.
Will you be going out? -Yes, I expect so.
I'm not sure if the shop stays open late, but I think so.
Can the machine be repaired? -I hope so.
Has the committee reached a decision? -Well, it seems so.
I'm travelling round the world. -Is that so?
Here I expect so means “I expect I'll be going out”. We cannot leave out so or use it.
NOT Yes, I expect./Yes, I expect it.

2 We can use these verbs and expressions in this pattern with so: be afraid, it appears/appeared, assume, be, believe, do • (2), expect, guess, hope, imagine, presume, say, it seems/seemed, suppose, suspect, tell (someone), think. We do not use know or be sure in this pattern.

The shop stays open late. -Yes, I know. NOT Yes, I know so.
-Are you sure? (NOT Are you sure so?)

3 There are two ways of forming a negative pattern.

Negative verb + so Positive verb + not

Will you be going out? -I don't expect so. Is this watch broken? -I hope not

Some verbs can form the negative with either pattern, e.g. “I don't suppose so” or “I suppose not”. They are appear, believe, say, seem and suppose.
Expect, imagine and think usually form the negative with so.
“I don't think so” is more usual than “I think not”, which is rather formal.
Assume, be afraid, guess, hope, presume and suspect form the negative with not.
Is this picture worth a lot of money? -I'm afraid not.
There's no use waiting any longer. –I guess not.