"a bit of doubt" is a correct and usable phrase in written English.
It means a small amount of uncertainty or hesitation. Example: After the recent events, there is still a bit of doubt lingering in my mind about his true intentions.
And there's quite a bit of doubt out there.
There was a bit of doubt as to the validity of the result".
"I think there was a bit of doubt about that after the first debate".
A bit of doubt will creep in and then he will get desperate.
We're just not there as yet; there's still a bit of doubt.
"There's obviously a bit of doubt there – which is good, because that obviously keeps them unsettled and keeps a bit of doubt in their camp," he told reporters on Tuesday.
"Chris didn't train today and I suppose that makes him a bit of a doubt for the Dunfermline game," he admitted.
There is a bit of a doubt at the trip on softer ground but he's by Dom Alco, they stay well and he looked like he was staying on up the hill when winning the Paddy Power [at Cheltenham] last year.
The chairman of a local Pavillion residents' group — about 200 people, mostly involved in farming and ranching, who live in proximity to the drilling sites — expressed gratitude to the E.P.A., and perhaps a bit of veiled doubt about the zeal of local and state regulators.
"He's not [bowling] quite at full pace, and I think the risk of going into five-day Test match with that injury, an injury that not too many people have had, just had a bit of a doubt about it," Cook added.
"Obviously as the week progresses we'll know more, but yes he's going to be a bit of a doubt," McLaughlin confirmed.
