We use "so" and "too" to agree with positive statements and "neither" and "either" to agree with negative statements. Specifically: - "So" is used at the beginning of a sentence to agree with a positive statement. "Too" is used at the end. - "Neither" is used at the beginning of a sentence to agree with a negative statement. "Either" is used at the end. - "Me too" and "me neither" are also used for agreement in informal contexts.

1. Agreement

2. I am too. I’m not either.

3. So am I (= I am too), So have I (= I have too)
-‘I'm tired.’ ‘So am I.’ (not ‘So I am.’)
- ‘I was late for work today.’ ‘So was John.’
- ‘I work in a bank.’ ‘So do I.’
- ‘We went to the cinema last night.’ ‘Did you? So did we.’
Neither am I (= I'm not either), Neither have I (= I haven't either)
- ‘I haven't got a key.’ ‘Neither have I.’ (not ‘Neither I have.’)
- ‘Ann can't cook.’ ‘Neither can Tom.’
- ‘I won't (= will not) be here tomorrow.’ ‘Neither will I.’
- ‘I never eat meat.’ ‘Neither do I.’
Nor … (= Neither):
- ‘I'm not married.’ ‘Nor am I.' (= Neither am I.)’

4. We use too and either at the end of a sentence.
We use too after a positive verb  :
- ‘I'm happy.’ ‘I'm happy too.’
- ‘I enjoyed the film.’ ‘I enjoyed it too.’
- Mary is a doctor. Her husband is a doctor too.
We use either after a negative verb  (am not / isn't / can't etc.):
- ‘I'm not happy.’ ‘I'm not happy either.’ (not ‘I'm not happy too.’)
- ‘I can't cook.’ ‘I can't either.’
- Bill doesn't watch TV. He doesn't read newspapers either.

5.  So am I
 Neither / Nor am I
 I am too
 I'm not either
 Me too
 Me neither
So….. …..too
Neither….. …..either

6. I like chocolate. I don’t like chocolate.
I do, too. I don’t like chocolate either.
So do I Neither do I.
Me too. Me neither.

7. am/is/are …
was/were …
So do/does …
did …
Neither have/has …
can/could…
Will / would …
must …
should

8. can you.
neither do they.
so do you
he won’t either.