“The past 12 months have seen the passing of the last WWI combat veteran, one of golf’s greatest players and the man who introduced the iPhone to the world,” wrote the BBC in 2011.

Hmm … Is this all about the Oxford comma? (With its lone comma, that sentence sounds as though Steve Jobs could have been a golf champion and the last surviving veteran of the first world war …) No, that’s for another time and place; this is about past and last — two adjectives that are very similar to look at and are sometimes synonymous, but are often actually lifetimes apart.

Recency and finality are what it’s all about here, and the fact that last can describe either state is what sometimes causes confusion and ambiguity. 

Take this sentence: “In the last few weeks, Jane sold most of her worldly goods.” Does that mean she sold her stuff recently, say in the previous month, before she moved abroad? Or could she have died many decades ago and sold her possessions in the final few weeks of her life? Only some meaningful context will provide the answer.

Using past instead of last there would remove any sense of ambiguity, since it describes the time leading up to the present: i.e. the recent past. (Which is a little paradoxical, if you think about it.) So if Jane was selling most of her worldly goods in the past few weeks, she is presumably still alive and well.

And it isn’t just with past that last gets confused: it often runs into trouble when it’s trying to suggest another kind of recency.

In an obituary last month for the writer Günter Grass, The Guardian described how “his last novel, 2002’s Crabwalk, dived into the sinking of the German liner Wilhelm Gustloff in 1945″. It’s pretty clear here — because we’re reading an obit — that the novel in question was Grass’s final one. But in the same newspaper just a day earlier, the musician Sam Lee, talking about a favorite author, said: “I’m a big fan of [Robert] Macfarlane’s work: I’m reading his last book, The Old Ways, at the moment.” If you don’t know anything about Macfarlane, you could be forgiven for wondering whether he’s stopped writing — because of a change of career or life status — or if Old Ways is his most recent work. Latest might be a wiser choice of word when this particular case of “recency versus finality” rears its ambiguous head.

The AP style guide suggests succinctly that you should “avoid the use of last as a synonym for latest if it might imply finality.

The Wall Street Journal‘s style & substance bulletin is more prescriptive (and amusingly detailed); they’ve really covered all their bases on this sometimes delicate subject:

● Avoid the use of last as a synonym for latest, to avoid implying finality. Saying “The company’s last announcement was made Thursday” is ambiguous, so use latest instead..

● Use past instead of last in other contexts to avoid the suggestion of finality: in the past 10 days; in the past 12 months.

● To prevent ambiguity, the word last should be avoided in references to earlier days in the current week or earlier months or seasons in the current year: On a Friday, for example, refer to the most recent Tuesday as this Tuesday, or use simply on Tuesday if the reference to the past is clear in context. This past Tuesday works as well, if the reference to the past isn’t clear.

● And in August, for example, refer to the most recent February as this February or use simply in February if the allusion to the past is clear in context. And in a December, refer to this summer if the allusion to the past is clear.

*   *   *