The phrase "a sign of how difficult" is correct and usable in written English.
It can be used to indicate that something serves as an indication or evidence of the level of difficulty of a situation or task.
Example: "The long hours and constant revisions were a sign of how difficult the project had become."
Alternatives: "an indication of the challenges" or "a reflection of the difficulty".
And that's just a sign of how difficult the diagnosis is.
But, perhaps in a sign of how difficult swift changes are to make to laws governing Indian affairs, the amendment is not certain to receive a vote.
In a sign of how difficult it will be to help Cyprus out of its financial black hole, Mr. Rehn gave no indications of when an assistance package would be finished.
But in a sign of how difficult the furor over his behavior may be to contain, he made clear he could not say for certain how many women or lewd images might yet surface.
The strong early sales of the iPhone 5 are also a sign of how difficult it's going to be for competitors like Nokia and Motorola Mobility to gain a foothold in the smartphone market.
But in a sign of how difficult it is to rally people around a single proposal: Dewey said the Taylors, an old Republican family that has supported Democrats and Republicans alike, were staying "neutral" on the carbon fee initiative.
It's an unfortunate sign of how difficult it will be to pass any kind of energy reform in Congress.8 38: In the end, I think there wasn't much the president could do to reassure the public in this speech.
HONG KONG — Apple has disabled its news app in China, according to a person with direct knowledge of the situation, the most recent sign of how difficult it can be for foreign companies to manage the strict rules governing media and online expression there.
There's a nervous, kinetic energy about him, a sign, perhaps, of how difficult it must be to go through life knowing you can never truly be free of two of America's most high-profile felons.
Perhaps the best sign of how difficult it is to know the economy's direction is that, as a group, the nation's professional forecasters have failed to predict all the recessions since the 1970s, according to data kept by the Philadelphia Fed.
It matters too because as one official source suggested, there just is "not enough political agreement yet" to push on, another sign of how difficult the government is finding it, trying to agree their own positions on how we leave the European Union, and how hard they know it will be to persuade not just the opposition, but their own side too.
