The phrase "a single curtain" is correct and usable in written English.
You can use it when referring to one curtain, often in contexts related to home decor, theater, or privacy.
Example: "She decided to hang a single curtain in the window to let in more light."
Alternatives: "one curtain" or "a lone curtain."
"But I haven't made a single curtain".
The audience clamoured for the composer to acknowledge the applause, but Massenet, always a shy man, declined to take even a single curtain call.
This initial construction consisted of a single curtain wall with towers, which now forms the inner circuit of the Theodosian Walls.
On Wednesday, the eight dancers, joined by Mr. Elkins, took a single, happy curtain call; but the applause went on long after, expressing the hope that these marvelous performers would take another bow.
The hangar was divided by a single fire curtain just forward of the aft aircraft elevator.
Its minimum height was 21 feet, and it was divided by a single fire curtain just forward of the aft aircraft elevator.
For a single-layer curtain it is known that the minimum flow rate required for initial stability can be violated by carefully reducing the flow rate below this point, which defines a hysteresis region.
Here, among the rows of empty windows, a single white lace curtain is seen.
A series of corrugated iron barns each centred around a bar houses girls in individual cells the size of a single bed with a curtain for privacy.
The clematis does not grow from a single place: there is a curtain of stems, all parallel at first, but splitting up like a bowl of spaghetti when they reach the branches of their host.
But late last year, the department, led by its first African-American commissioner, John B. King Jr., decided to delicately pull back the curtain — for a single hour, once a month — to allow people to make up their own minds about the mural, though with new explanatory brochures and placards to put the painting in context.
