The phrase "hard to guarantee" is correct and usable in written English.
You can use it to describe something that is uncertain, unreliable or difficult to commit to. For example, "With the current circumstances, it's hard to guarantee that the event will be able to go ahead as planned."
It's hard to guarantee it, but with this author I can".
In Pakistan, it is hard to guarantee the security of these materials during transportation.
Ideas that go viral are great but are hard to guarantee.
Still, with that strategy alone, it's hard to guarantee that there is not any sensitive information on your hard drive.
It's hard to guarantee the "same great taste" in a scientifically advantaged product when no one is sure just what that taste is.
Ramon Saul Sanchez, who leads the anti-Castro group Movimiento Democracia, said he hoped that any protest would be peaceful, but that it was hard to guarantee.
And that highlights the problems publishers face in a turbulent, topsy-turvy marketplace where success seems ever harder to guarantee.
Besides coping with the problems posed by a turbulent, topsy-turvy marketplace where success is ever harder to guarantee, publishers faced industry upheaval.
Only hours before General Ozkok's remarks, a senior member in the ruling Justice and Development Party said that Turkey's leaders were determined to take the measure back to the Parliament and push harder to guarantee its success.
They will not, however, be able to attach an FPS file to payments, and the report says this will make it harder to guarantee the accuracy of the information.
An advantage of a unified system of records is that the NHS has comparable data across big swathes of the population; that is harder to guarantee if the population is divided between insurers.Just as the NHS influences other countries, could it learn from them?
