attest to

基本解释

Several witnesses can attest to her good character.
好幾個証人可以証明他爲人正派。
I can attest to the absolute truth of his statement.
我可以証實他的話是千真萬確的。
《新英漢大辤典》
All of us who are mothers can attest to the fact that there are times when our children drive us to distraction.
我們這些做媽媽的人都能証明，事實上有時候我們的孩子也會讓我們心煩意亂。

It doesn't particularly attest to any level of accomplishment.
She may not use God's name in a false oath, to attest to or swear by a false oath. She is to honor God's Sabbath day, and honor parental authority, which is arguably an extension of God's authority.
她不可以以上帝的名義宣假誓,她應該敬重上帝的安息日，敬重父母親的,權威，盡琯人們對它是否是上帝權威的延伸是有爭議的。
耶魯公開課 - 舊約導論課程節選
John Freeman can attest to that. He says he received professional surgery and excellent care from attentive doctors and nurses.

Our Jetta was a Greasecar conversion, and I can attest to very little French Fry smell.
FORBES: You Won't Smell Like McDonald's If You Drive a French Fry Car--The Best Oil Comes From Chinese Food Anyway