The phrase "a fair grasp" is correct and usable in written English.
It can be used to indicate a reasonable or adequate understanding of a subject or concept.
Example: "After studying for several weeks, she felt she had a fair grasp of the material covered in the course."
Alternatives: "a solid understanding" or "a good comprehension".
With a German husband, 13 years in Germany and three children born here, Stacy Wiedenmann of Chicago thought she had a fair grasp of her adoptive land.
Although the Threads are not designed to be vessels of content, it is often necessary for an educator to have a fair grasp of the geometry, physics, astronomy, or other disciplines relevant to the experience before feeling comfortable about facilitating the Thread in their classroom.
One gains a fair grasp of the variety of ways in which people properly use the term 'integrity' by examining conditions commonly accepted to defeat or diminish a person's integrity.
I never really got a fair grasp of university life abroad until I actually lived it.
If you want to meet someone named John or Mary or David, who has good teeth (or at least most of them), a decent haircut and low body fat, who'd rather sit on a toilet than piss off the porch, who might walk in the woods without taking a gun, who uses deodorant and has a fair grasp of standard English, then don't come in.
The choices are sufficiently complex that there is a fair chance he doesn't fully grasp that he is making them.
"It's hard to even grasp what's a fair market price now.
Still, the picture's reach never exceeds its grasp, and it offers a fair amount of the gross-out stuff kids love.
To be a fair DM, you are expected to have a strong grasp of the rules of the game.
Avoid making French pastries until you have a good grasp of working with pastry and a fair understanding of its properties.
For a fair labor campaign to work, it needs an easy-to-grasp rating system and a recognizable logo.
