The phrase "are exceedingly grateful" is correct and usable in written English.
You can use it to express a strong sense of thankfulness or appreciation, often in formal or heartfelt contexts.
Example: "We are exceedingly grateful for your support during this challenging time."
Alternatives: "are extremely thankful" or "are very appreciative".
Those of us privileged to have known him and learned from him are exceedingly grateful for his life.
Speaking in Paris, he said that he and President Obama are "exceedingly grateful to have France by our side" in backing a political solution and "limited" military action over Syria.
My wife and I recently celebrated our fifth wedding anniversary, a milestone which our early thirty-something selves are exceedingly grateful for, to God and one another.
We are exceedingly grateful to those who donated their bodies to the Anatomy Laboratory at BSMS for use in anatomical examination.
Most residents there — nearly all of whom knew the agony that dengue causes — were exceedingly grateful.
In the letters, he said that he would be "exceedingly grateful" for help in "tracing and assisting" his mother.
"As I always said, I only ever wanted to be a strong local representative and I am exceedingly grateful they gave me that chance".
Julia Roberts, whom they found for a breakout role in Mystic Pizza, and all the previously unknown teenage heartthrobs of The Outsiders (Tom Cruise, Matt Dillon, Rob Lowe) must be exceedingly grateful for their eye.
I'm exceedingly grateful to Tim for his many contributions to the business, and I believe his support over the next few months will continue to strengthen Oath's market potential.
"I'm exceedingly grateful to Tim for his many contributions to the business, and I believe his support over the next few months will continue to strengthen Oath's market potential," Vestberg said in an internal memo.
It is indeed very heartening to see that our friends and colleagues and research collaborators, especially Prof. Dr. İsmail Naci Cangül and Prof. Dr. Yilmaz Şimşek, organized yet another International Dedication Congress in my honour, for which I am exceedingly grateful to one and all of them.
