Learn English – Either….and…or? Either…or…or

either-or

"Use the installation wizard to choose between either a and b, or to install both of them simultaneously."
or is it
"Use the installation wizard to choose between either a or b, or to install both of them simultaneously."

Also, is there a comma before the second or, am I omitting any other comma(s), is it grammatically correct to have such a structure even, should I restructure it ;0

Best Answer

"Choose either A and B, or C" means, in general, two choices:

  • A and B
  • C

"Choose either A or B, or C" means, in general, three choices:

  • A
  • B
  • C

If "C" is equivalent to "A and B",
"Choose either A and B, or C" gives no choice at all: it always means "A and B".
"Choose either A or B, or C" in this case means three choices:

  • A
  • B
  • A and B

And, in any case, the word "between" is superfluous in this construction.

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