The phrase "a challenge can be" is correct and usable in written English.
You can use it when discussing the nature or characteristics of a challenge in various contexts, such as personal growth, work, or problem-solving.
Example: "A challenge can be an opportunity for growth and learning if approached with the right mindset."
Alternatives: "a challenge may be" or "a challenge could be".
A challenge can be fun, but cooking shouldn't be intimidating.
But because such a challenge can be tabled by the vote of a simple majority, and because there are fifty-five Republican senators, the ruling would be upheld.
This is a ruling by the highest court in the EU, and it is difficult to see that a challenge can be brought again any time soon.
For instance, the whole issue of the overseas soldiers' ballots can't be resolved until such time as the election returns are certified and a challenge can be made as to whatever standards are being used to not include those ballots.
Barcelona are going to have to survive without Messi for around eight weeks and here was a timely reminder that Suárez, never one to shy away from a challenge, can be a winning machine as well.
In a note explaining the need for a change, Willsman wrote: "Unfortunately, the lack of precise clarity in the way the rule is written is exploited by hostile media speculation claiming that a challenge can be mounted against our current leader Jeremy Corbyn with him excluded from the ballot paper.
Under party rules she has a year's grace before a similar challenge can be launched.
Authoritarian instincts there are still so strong, a political challenge can be seen as a coup attempt.
Much of Germany's state aid goes to firms in the east, where a commission challenge can be especially sensitive.
Changes in renal hemodynamics during a fluid challenge can be observed by Doppler ultrasonography before urine output increases.
We love to hear about how an impossible challenge can be turned into a raging success.
