The phrase "a difficult thing to achieve" is correct and usable in written English.
It can be used when discussing challenges or obstacles that make accomplishing a task or goal hard.
Example: "Completing a marathon without prior training is a difficult thing to achieve."
Alternatives: "a challenging task" or "a tough goal to reach".
It is a difficult thing to achieve.
But they have long maintained that it is a difficult thing to achieve.
In 1932 a writer in Architecture magazine noted that "provision against damage to the glass by objects falling from the upper stories remains a difficult thing to achieve".
Rebel groups, among them the jihadist Jabhat al-Nusra, say they are trying to reach the Mediterranean coast, where they hope to open a supply line, a difficult thing to achieve with the Syrian military maintaining dominance over air and sea.
But price stability is a difficult thing to achieve.
Simultaneous consideration of both mean and standard deviation is a critical component of statistical reasoning, but is, apparently, a difficult thing to achieve.
This is a very difficult thing to achieve successfully, though; unless a TV's processing systems are exceptional you may see such issues as color balance problems, unnatural color tones, bleached whites, forced and detail-light dark scenes, plus exaggerated video noise.
This is an increasingly difficult thing to achieve in an age of streaming and among a plethora of new franchises.
It's still an incredibly difficult thing to achieve but we have always believed that a city and a region the size of Nottingham could support a Premiership rugby side and our job is to make that happen".
"It is a very, very difficult thing to achieve.
"There's ability and an opportunity to score goals, which is the most difficult thing to achieve - you have to spend a lot of money to correct it.
