So or neither

So and neither are used to show agreement or disagreement with a statement made by another person or concerning another person.

So

So is used to agree with a statement which is affirmative.
John: 'I like pizza.'
Peter: 'So do I.'

Here are some examples. Notice that if an auxiliary verb is used in the statement it matches in the agreeing reply.

A: I speak Russian. → B: So does David.
A: Peter is tired. → B: So is John.
A: Mark can play the saxophone. →B: So can Edward.
A: I've travelled a lot. → B: So have I.

Neither

Neither is used to agree with a negative statement:
Mark: 'I don't like classical music.'
Fred: 'Neither do I.'

As with 'so' the auxiliary in the reply with 'neither' agrees with the statement:
A:  I don't speak Russian. → B: Neither do I.
A: Peter isn't happy. →B: Neither am I.
A: I can't play any musical instruments. →B: Neither can I.
A: I haven't yet been to Paris. → B: Neither have I.

Neither or either

Compare these sentences:
A:  I don't like broccoli. → B: Neither do I. - I don't either.
'not + either' can be used instead of 'neither' with the same meaning.

Remember: The verb 'hate' has a negative meaning but it is used in an affirmative statement.
A: I hate broccoli. → B: So do I (hate broccoli) and NOT 'Neither do I.'

Choose the correct reply to the following statement:

• 1. John hates waking up early. (John hates it too) -
  
  So does John.
  Neither does John.
  
  
• 2. Peter arrived late for the meeting. (Mark also arrived late.) -
  
  Neither did Mark.
  So did Mark.
  
  
• 3. They couldn’t speak French. (We also couldn’t speak French) -
  
  So could we.
  Neither could we.
  
  
• 4. Too much tea is bad for you. (Coffee is also bad) -
  
  So is coffee.
  Neither is coffee
  
  
• 5. Sarah hates being late. (John also hates being late.) -
  
  Neither does John.
  So does John.
  
  
• 6. Mark has a very well paid job. (Peter also has a well paid job.) -
  
  So does Peter.
  Neither does Peter.
  
  
• 7. I’d love to live near the seas. (the next speaker agrees with the statement) -
  
  Neither would I.
  so would I.
  
  
• 8. John would hate life in the city. (Peter would also hate it) -
  
  Neither would Peter.
  So would Peter.
  
  
• 9. David just didn’t understand the new proposals. (Mark also didn’t understand) -
  
  So did Mark.
  Mark didn’t either.