Equivalent of "both" when referring to three or more items?

What would be the correct word to use when referring to three or more items, in the same manner as the word both?

For example, using two words, with the word both:

"There are several recommendations I have to further improve the sites — both to improve their profit, and decrease their cost."

Using three words, with a blank space in place of the correct word:

"There are several recommendations I have to further improve the sites — _ to improve their profit, decrease their cost and improve their usability."

So, what would be the correct word to use in place of the __?

Solution 1:

At that point I'd probably pick out one of the list for special attention using "not only ... but":

There are several recommendations I have to further improve the sites, not only to improve their profit but to decrease their cost and improve their usability.

I'd cut that down further, though:

I have several recommendations to improve the sites—not only to improve their profit, but to decrease their cost and improve their usability.

Solution 2:

Both is the suppletive variant of *all two, which is not grammatical English.

Suppletion is the irregular grammatical phenomenon of substituting a different word or root. Like using went instead of *goed, or ever instead of *anywhen. It's not too common in English, but it occurs.

So the equivalent of both, for n>2, is All n: all three, all four, all seventy-seven of them.

Solution 3:

I would leave out the word altogether, the second example you give makes perfect sense as it stands:

There are several recommendations I have to further improve the sites; to improve their profit, decrease their cost and improve their usability.

Or, if I'm going to be really picky, and remove the doubling up of the phrase "improve":

There are several recommendations I have to further improve the sites' profit, decrease their costs and improve their usability.

Solution 4:

There are two usual alternatives to refer to the three items:

1. "not only...., but...and..."
2. "both...and...as well as..."

The first alternative - "not only..., but...and..." - has a limitation: it is basically intended to refer to two items, but is adapted to fit in three items by adding "and...". Moreover, "not only..." puts less emphasis on the first item.

The second alternative - "both...and...as well as..." - puts an emphasis on the last item.

Therefore, the best way to refer to three items is to use "...: firstly...; secondly...; lastly...". In the instant case, the sentence could be written as follows:

"There are several recommendations I have to further improve the sites: firstly, to improve their profit; secondly, to decrease their cost; lastly, to improve their usability."

Solution 5:

You don't need a word there at all.

There are several recommendations I have to further improve the sites — to improve their profitability, decrease their cost and improve their usability.

A follow-up suggestion, which you didn't ask for, is to remove the triple repetition of the word "improve".

I propose several recommendations for the sites to raise their profitability, cut their cost, and improve their usability.

Furthermore, a cost decrease generally implies a profit increase, so that may be redundant.

I propose several recommendations for the sites to improve both their profitability and their usability.