The phrase "a secondary one" is correct and usable in written English.
It can be used to refer to something that is not primary or main, often in contexts where multiple options or levels are being discussed.
Example: "While the primary goal of the project is to increase sales, a secondary one is to improve customer satisfaction."
Alternatives: "a subordinate one" or "a minor one."
At this point they are supporting more than 30 languages, and the app lets you specify a primary language, then a secondary one, and so on.
A secondary one, in fact.
A secondary one claims that Miliband gave a "commanding performance" when launching Labour's mainfesto.
Her role in the crime, while not negligible, was a secondary one; she didn't even carry a gun.
Over and over, we practiced blurting out a primary clue ("Old-fashioned ladies' underwear") and then a secondary one ("Blank Junction").
In every pair, both spells violated the same fundamental principle of physics, biology, or psychology, but each varied in how much it violated a secondary one.
Participants were 60 secondary school students: 33 in a Secondary-One (equivalent to 7th grade in the U.S. system) chemistry class, with mean age of 13 years; and 27 in a Secondary-Four (equivalent to 10th grade in the U.S. system) mathematics class, with average age of 16 years.
Since HRQoL had been defined as a central secondary outcome, the primary outcome was replaced by a former secondary one without changing elements or procedures of the intervention itself.
Figures 4A and B reveal the location of the most likely cluster and of a small secondary one, respectively.
Only two randomised trials used it as a secondary outcome, one with and one without positive results [ 10], [ 11].
Truman's principal reason for deciding to drop the bomb on Japan was to bring the war in the Pacific to a quick end, but his secondary one was to erect a psychological obstacle to any Soviet plans for postwar expansion.
