The phrase "a decent grasp of" is correct and usable in written English.
It can be used to indicate a satisfactory understanding or knowledge of a subject or skill.
Example: "To succeed in this course, you should have a decent grasp of basic mathematics."
Alternatives: "a good understanding of" or "a solid knowledge of".
Though Fire Over England is fictionalised, it's entertaining and has a decent grasp of the historical context.
The outspoken ex-Millwall chair has caused more than the odd ripple or two on Dyke's FA Commission, but has a decent grasp of what the game needs.
Ms. Aselton, who is married to Mr. Duplass and developed the story with him, shows a decent grasp of how to build tension.
"As anyone with a decent grasp of physics, biology, and materials science understands, Santa's advertised abilities are perfectly plausible," writes Mone.
Just as the Moneyball sensibility transformed professional sports worldwide, the ability to perform well in fantasy sports leagues signals that somebody has a decent grasp of probabilities, risks, and opportunities in a competitively transparent and transparently competitive environment.
Though my father spoke with a heavy accent, I had always thought he had a decent grasp of the English language, but as my own grammatical prowess grew, I saw this wasn't the case at all.
I thought I had a decent grasp on the number of things that I owned.
It has meant that while the actor feels she has a decent grasp on the Jewish part of herself, the African American part is slipperier altogether – "more patchworky", she says.
By now, managers have a decent grasp on their teams' strengths and weaknesses.
He'd worked with her from the start; I assume he had a decent grasp on when an Amy song was finished or not.
Still, in a networked world every small company needs a decent grasp on technology in order to compete.
