both

English as a Second Language English Vocabulary, Grammar and Idioms
1
  1. Both of boys like hamburgers.
  2. Both of the boys like hamburgers.
  3. Both of us don’t swim regularly.
  4. Neither of us swim regularly.
    Please correct them.
    Thanks.
2

  1. incorrect.
    Both (the) boys like hamburgers.

  2. incorrect, as the sentence uses the negative ‘don’t’. Use 4.

3

Beeesneees,
Is # 2 OK?
3a. Both of us swim regularly.
Is this sentence OK?
Thanks.

4

If 2 and 4 were not okay I would have mentioned them.

‘Both of us swim regularly’ is positive, so is okay.

5

Beeesneees,
1b. Both of us didn’t want to see the police, but wanted to solve the problem mutually.
1b. Neither of us wanted to see the police, but wanted to solve the problem mutually.
2a. They both have never held elected office.
2b. Neither has ever held elected office.
Please correct the above.
Thanks.

6

All those are negative (didn’t want to) so require ‘neither’. To use ‘both’ is incorrect in each case.