The phrase 'have doubts whether' is correct and usable in written English.
It is often used when expressing uncertainty. For example: "I have doubts whether I should accept the job offer."
I have doubts whether we shall come through".
But some still have doubts whether that armor is thick enough to withstand another big shock.
"We have doubts whether the insurance scheme will work, I mean durably work," Mr. Matthews said.
Many economists, however, have doubts whether the recovery in consumer spending will last because incomes in Japan, like prices, have been falling.
"It's good news that N.H.T.S.A. is being an aggressive regulator, but you have to have doubts whether a $16 million fine is going to have a deterrent effect on automobile companies that are worth billions of dollars," Mr. Shapiro said.
"I have doubts whether people will be wearing glasses to play games at home.
Some analysts have doubted whether Commerzbank could meet the requirement without additional government help.
True, some journalists have doubted whether Harry really did revive Bash Kazi.
Some have doubted whether the al-Qaida leader was ever present at Tora Bora.
Elon Musk, Tesla's chief executive, has also battled critics who have doubted whether the company could ever succeed financially.
Some legal commentators have doubted whether Assange would have strong grounds to take his appeal to the court in Strasbourg.
