' Both / both of  /   neither / neither of /   either / either of '
  
 A/ We use both/ neither/ either for two things. You can use these words with a noun (both books, neither book etc.).
 For example, you are talking about going out to eat this evening. There are two restaurants where you can go. You say:
 • Bothrestaurants are very good, (not 'the both restaurants')
 • Neitherrestaurant is expensive.
 • We can go to eitherrestaurant. I don't mind, (either = one or the other, it doesn't matter which one)
 
 B/ Both of... / neither of... / either of...
 
 When you use both/ neither/ either + of, you always need the... / these/ those... / my/ your/ his/
 Tom's... (etc.). You cannot say 'both of restaurants'. You have to say 'both of the restaurants', 'both of those restaurants' etc.:
 
 • Bothof these restaurants are very good.
 • Neitherof the restaurants we went to was (or were) expensive.
 • I haven't been to eitherof those restaurants. (= I haven't been to one or the other) You don't need ofafterboth. So you can say:
 • Bothmy parents are from London,   or    Both of my parents...
 
 You can use bothof / neitherof / eitherof + us/you/them:
 • (talking to two people) Can eitherof you speak Spanish?
 • I asked two people the way to the station but neither of them knew. 
 
 You must say 'both ofbeforeus/ you/ them (of is necessary):
 • Both of us were very tired, (not 'Both us were...')
 
 After neitherof... a singular or a plural verb is possible:
 • Neither of the children wants (or want) to go to bed.
 
 C/ You can also use both/ neither/ either alone:
 • I couldn't decide which of the two shirts to buy. I liked both, (or I liked bothof them.)
 • 'Is your friend British or American?'  'Neither. She's Australian.'
 • 'Do you want tea or coffee?' 'Either. I don't mind.'
  
 D/ You can say:
  
      Both... and...:               Both Ann and Tom were late.
                                         I was both tired and hungry when I arrived home.
  
 Neither... nor...:            Neither Liz nor Robin came to the party.
                                         She said she would contact me but she neither wrote nor phoned.
  
 Either... or...:                I'm not sure where he's from. He's either Spanish or Italian.
                                         Either you apologise or I'll never speak to you again.