What is the difference between "better yet" and " better still"?

Solution 1:

In the most common case they are completely indistinguishable — and in recent years they’ve come to be used with comparable frequency, as I show in the graph below.

That said, there can be differences between them in certain “rescue readings” given enough set up, but these differences are ones that Google N-gram is useless for distinguishing because it takes more context.

Mostly the differences are because yet and still do not themselves work quite the same way, and so even when you mix better into the equation, there can still sometimes be a few minor but lingering differences remaining.

For one thing, you can swap the order to change better still into still better much more easily than you can change better yet into yet better. The last of these does not work:

Better still, do it yourself.

Better yet, do it yourself.

Still better, do it yourself.

*Yet better, do it yourself.

Notice the difference in magnitudes here in this revised Google N-gram:

Another way to look at that is like this, showing ratios of 18 ∶ 19 ∶ 1 ∶ 12, respectively:

• 36.2% for better yet
• 37.8% for better still
• 01.7% for yet better
• 24.2% for still better

You can say this easily enough:

Still better would be making it attractive to people to be less reliant on cars and to use less carbon-intense forms of transportation, especially for short journeys.

But you cannot do that with yet, at least not so naturally.

For another thing, yet is a negative-polarity item, as John Lawler explains here and here. So these are ok:

Are you better yet?

I’m not better yet.

But these are not:

Are you better *still?

I’m not better *still.

However, you can put the still first when you have some follow-on bits:

Are you still better than he is?

Solution 2:

In modern American English yet is normally reserved for use as a negative polarity item (NPI; restricted to negated clauses, questions, or protasis clauses). So you can say:

I'm not hungry yet.
?I am hungry yet.

The latter would be understood, but it is uncommon to hear. Use of yet outside of NPI contexts is uncommon now, but was not always. Yet used to have a broader overall meaning. It could mean more, as in this example from 1497:

Wages of maryners..ixli vijs. Vitayle..vijli xxd. Yet Wages of maryners..iiijli xs xd

Yet here is used similarly to how more would today. Now the meaning is restricted to that of "in continuation" (without the sense of "in addition"). Use of yet outside of NPI contexts was formerly frequent, but now is coded archaic in the Oxford English Dictionary.

At the time the expression better yet was coined, yet was used in places where still is now. Another google ngram will show still surpassing yet overall in the mid ninteenth century. I'd guess this is the time at which yet started to become restricted to NPI environments.

If that were the case, then better yet would have solidified into a fixed expression (whose meaning did not have to be computed from its parts on the spot [even though, in principle it could]), by this time, so the drift of yet to become restricted to NPI contexts would have left better yet stranded. I'd venture that better still doesn't qualify as a fixed expression today, but don't know what data there would be to show that.

Solution 3:

One way to test whether these are equivalent is to use both in a piece of text, then swap the position and see if that makes any difference. if one of them was slightly better than the other, then one of the orderings should feel wrong.

eg

It's better to brew your own coffee than use instant. Better yet: grind your own beans. Better still: make sure those beans are fresh.

It's better to brew your own coffee than use instant. Better still: grind your own beans. Better yet: make sure those beans are fresh.

To me, the first one feels slightly more natural, implying that (for me at least) "better still" slightly trumps "better yet". But, this might just be my opinion. I think that both are valid, anyway. You could also repeat either of them, eg

It's better to brew your own coffee than use instant. Better yet: grind your own beans. Better yet: make sure those beans are fresh.

but i think it's better to avoid the repetition.