# Can we always replace "one last" with "a last"? For example: "She took one last draw from the cigarette." → "She took a last draw from the cigarette."

As I understand, since we can use "a" instead of "one" (e.g. "one million" = "a million"), then we can use "a last" instead of "one last".

To check it, I found some examples:

oxfordlearnersdictionaries.com:
(1) She took one last draw from the cigarette.
my variant:
(2) She took a last draw from the cigarette.

oxfordlearnersdictionaries.com (from the section "Extra Examples" under the first meaning):
(3) She spun the roulette wheel one last time.
my variant:
(4) She spun the roulette wheel a last time.

oxfordlearnersdictionaries.com (from the section "Extra Examples" under the third meaning):
(5) The teacher gave her one last chance to prove she could behave.
my variant:
(6) The teacher gave her a last chance to prove she could behave.

cambridge.org (from the section "More examples" under the first meaning):
(7) The doctors made one last desperate attempt to save the boy's life.
my variant:
(8) The doctors made a last desperate attempt to save the boy's life.

Is there any difference between them?
If it is, then what is it?

Also I found the sentence that has "a last".
I'm curious to compare it with one having "one last".

collinsdictionary.com:
(9) She took a last look in the mirror.
my variant:
(10) She took one last look in the mirror.

What's the difference between them?

• Yes, you can always replace a by one in these contexts. Using that (less common) alternative adds emphasis. Dec 22, 2023 at 13:04

While a last and one last are typically interchangeable, there is a slight difference in meaning. You also should consider the last as part of this group:

She took one last draw from the cigarette.

She only took one draw. But there might have been more than one left.

She took a last draw from the cigarette.

It's conceivable that she could take or could have taken another last draw.

She took the last draw from the cigarette.

There was only one draw left and she took it.

• You've included the definite article, which normally does change the meaning. But OP asked about a and one, a choice which doesn't change the meaning. Except that one "emphasizes" the attribute last. Whether you smoked one last cigarette or a last cigarette has no implications for whether there might be any cigarettes left in the packet. But if you smoked the last cigarette, that strongly implies the packet is now empty. Dec 22, 2023 at 17:37

"One" emphasizes that there is only one. "A" implies "one" but doesn't give this emphasis.

So, "He made one last try" clearly says that this was the absolute last. If this doesn't work, he gives up. "He made a last try" COULD mean the same thing, but doesn't emphasize that if this doesn't work he's giving up.