Is "not but" an idiom? What does "one" refer to here?
"Not [number] but [bigger number]" is an expression that is often used to add emphasis in a sentence. When the speaker says "pulling not one but two all-nighters," he means that he pulled not one all-nighter but two all-nighters, indicating that the number of all-nighters he pulled is significant. "One" refers to the "all-nighters" that follows, and it is not necessary to include the word twice in the same phrase, so it is usually only used in the latter half of the sentence in this grammar pattern. Ex: I bought not one but two shirts yesterday. ("One" refers to "shirts" here) Ex: I have not one but three poodles. ("One" refers to "poodles" here)
Get more Native English Expressions >