The phrase "a while to gain" is correct and usable in written English.
It can be used when referring to the time it takes to achieve or acquire something.
Example: "It took a while to gain the trust of my colleagues after the incident."
Alternatives: "some time to acquire" or "a period to achieve".
It will take a while to gain back trust again".
It took a while to gain the trust of other artists, but eventually he won them over with his paintings, often surreal landscapes evoking the forces of nature.
The mother of the murdered teenager Stephen Lawrence has said it will "take a while to gain back trust" after she met Britain's most senior policeman to discuss claims that undercover officers hunted for information to smear her family.
"These kids took a while to gain confidence, but by the end of the summer, their experimental work was as good or better than a lot of our graduate students'," Dr. Lim said.
Cryptocurrencies were always going to take a while to gain mainstream acceptance.
Perhaps our best defense is to unplug for a while to gain some perspective.
"It has taken us Pakeha New Zealanders a little while to gain an appreciation of what is special here and to really be committed to its protection and survival," Smith said, using the Maori word for European.
He uses the abduction of the young Israeli soldier Gilad Shalit in 2006, snatched by Hamas as he was on patrol near the Gaza Strip, as the focal point for his even-handed account, which takes a little while to gain steam after a somewhat cliché-riddled opening.
I'd swim several laps at the same pace as the swimmer in an adjacent lane, then let him get out in front of me for a while, only to gain on and then overtake him just before I touched the wall after what I'd decided was the final lap.
Mitsubishi's i MiEV has been bouncing around for a while, trying to gain traction for electric cars.
The response may take a while to filter through and gain the mindshare, she believes, but we're about to be hit by a tsunami of interest from the corporate sector.
