The phrase "alone sustain" is not correct in standard written English.
It may be intended to convey the idea of something being able to support or maintain itself independently, but it lacks clarity and proper grammatical structure.
Example: "The resources available in the region alone sustain the local economy."
Alternatives: "sustain by itself" or "support independently".
How can better remuneration alone sustain them in the game?
How can so many candidates build up, let alone sustain the momentum needed for a credible attempt to win the party's nomination over such a long time period?
But the Bruins dominated puck possession early, registering the first seven shots on goal as the Rangers struggled to develop — let alone sustain — offensive continuity.
But the music industry has changed dramatically in the last nine years, and the novelty of an "Idol" win may no longer be enough to propel a winner's album sales, let alone sustain a career.
Christopher Tookey writes: "Diana the movie is not as tacky or sensationalist as one might fear...The trouble is that in being so careful and eager not to offend, the film is a more than a little tedious, with a lightweight, romantic storyline that fails to surprise, let alone sustain a movie that lasts nearly two hours.
With these works, script instructors vainly struggle to gather functional information that could even support let alone sustain any sensible or productive script course.
The Tribal Center building alone sustained over a million dollars in damage.
Still, economic stability, let alone sustained recovery, remained well out of sight.
Their work provides a detailed scientific analysis of the wreckage time's chariot leaves behind: The face alone sustains almost two dozen separate assaults, from sunken cheeks to larger ears (the cartilage actually grows).
For Labour – still holding 41 of the 59 Scottish seats at Westminster – there is an understanding that its long-vanished supremacy in the streets (a myth that has been on life-support for a while now) will not easily be recovered, let alone sustained.
But in Greece's case, it had become clear that high growth--let alone sustained high growth--was not going to come soon enough.
