The phrase "adept at understanding" is correct and usable in written English.
You can use it to describe someone who is skilled or proficient in comprehending or grasping concepts, ideas, or information.
Example: "She is adept at understanding complex theories, making her an invaluable asset to the research team."
Alternatives: "skilled in comprehension" or "proficient at grasping".
Are they adept at understanding the plot and the language?
Most young children, experts now say, are also more adept at understanding some abstract concepts -- basic notions of biology, for example -- than previously believed.
— This entrepreneurial city, the largest along the 981-mile Ohio River, is adept at understanding how geography, resources and new markets can be turned into business opportunities.
Building this fractal — and seeing participants who never thought of themselves as mathematically inclined become adept at understanding the complex spatial relationships — got me thinking about the experimental side of mathematics.
Some bands bring their own engineers, but many use the in-house crew, all of whom seem to be adept at understanding the needs of a variety of musics, from dubstep to folk, reggae to rock, or jazz to singer-songwriter acoustic softness.
And because Gemini is the "androgynous" sign of the zodiac, this mother is equally adept at understanding the pressures her son or daughter is going through at every age.
The more adept you are at understanding each other's needs, the better the relationship fares.
Humans are adept at network visualization, and at understanding subtle implications among the network connections.
He was adept at planning long marches through unknown territory, understanding that he not only had thousands of men to manage efficiently, but that a huge amount of supplies were required to adequately feed and sustain his army.
Because he's adept at using his eyes to manipulate coverage and displays an understanding of how to adjust his formations to get a mismatch before the snap, he's well ahead of the game as an N.F.L. prospect.
Thomson demonstrates a subtle understanding of the mind-set of the actor, adept at storytelling, spying, lying, and secrecy.
