Both, either and neither

1. Both, either and neither

Both, either and neither are particles that allow us to give information about two elements.

2. The partícle both

• Both is used when we talk about something that affects, involves or connects two people or things. It is used in affirmative sentences and precedes a plural noun. We can omit the noun when we know who or what we are referring to.
  
  Both tyres are flat.

  I like both.
• It can be followed by the preposition of, although it's optional. However, we must use of when both precedes the object pronouns us, you (second person plural) and them.
  I've read both (of) these books.

  I've read both of them.

• Both can also be used with verbs. Its position in the sentence will be before the main verb, but after the verb to be.
  They are both thinking the same.

  They both like this activity.
• Both can be used with the particle and to express two characteristics related to the same element, or that two people or things share one or more characteristics.
  
  This car is both smart and sporty.

  In this example we have an element (the car) that shares two characteristics (elegant and sporty).

  Both Mary and Jane like rap.

  In this example we have two elements (Mary and Jane) who share one characteristic (rap).

3. The particle either

• Either is used in affirmative and interrogative sentences when we want to refer to one or the other of two people or things, especially when it doesn't matter which. In negative sentences, it is used to show that the negative statement is true for the two people or things. It precedes a singular noun, which can be omitted when we know who or what we are referring to.
  
  Either option will do.

  Which one do you want? Either
• It is followed by the preposition of before a plural noun preceded by a determiner (the, my, these...), or when it precedes a plural object pronoun.
  
  You can't take either of these blankets.

  Do either of you know the new boss?
• We can use either with the particle or to express two things:
  

  - An alternative and/or choice in affirmative sentences. 

  - In negative sentences when we want to say that something is not true of two things, people...

  You can hand the essay in either today or tomorrow.

  In this example you can choose between two options (today or tomorrow). The verb is positive.

  I don't have either a pen or a pencil.

  In this example of the two options (pen or pencil) you don't have any. The verb is negative.

4 The particle neither

• The particle neither is used in phrases with an affirmative verb to express that something negative applies to two people, things... It precedes a singular noun, which can be omitted when we know who or what we are referring to.
  
  Neither hotel has a swimming pool.

  Which of these comics do you prefer? Neither.
• It is followed by the preposition of before a plural noun preceded by a determiner (the, my, these...), or when it precedes a plural object pronoun.
  
  Neither of these CDs is mine.

  Neither of us has ridden a horse before.
• We can use neither with the particle nor when mentioning two things are not true or possible.
  Neither he nor she knows where they have to go.

  They can neither work nor study.

5. How to use either...or and neither... nor

• Either...or and neither...nor are used to express the same. However, either..or will be used with a negative verb and neither..nor with a positive verb.
  
  He doesn't like either wine or beer.

  He likes neither wine nor beer.
• With either...or and neither...nor, the verb is used in singular when we have two singular nouns. When one of the nouns is in plural, it is usually placed next to the verb, which will also be used in plural.
  Either my father or my mother is going to take us to the concert.

  In this example, both father and mother are singular nouns, and therefore the verb is in singular, is.

  Neither the table nor the chairs have arrived yet.

  In this example we have a singular noun, table, and a plural noun, chairs, which we have placed next to the plural verb, have.

  In this type of constructions, the grammatical category of the two elements expressed between the particles and, or and nor must be the same (noun, noun; verb, verb...).

  They both live and work in London.

  They go to work neither by car nor by bus.

Remember!