have a (good/solid/sound/etc.) grasp of/on (something)

have a (good/solid/sound/etc.) grasp of/on (something)

To have a firm, clear understanding or determination of something. I hope everyone has a solid grasp of the material, as you'll be tested on it next week. I thought I had a pretty good grasp on English idioms, but I don't understand this one at all!
See also: grasp, have, of, on, solid, sound
Farlex Dictionary of Idioms.

have a grasp of

see under get a fix on.
See also: grasp, have, of
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • grasp
  • grasp of
  • a (good/solid/sound/etc.) grasp of/on (something)
  • have a grasp of
  • get a (good/solid/sound/etc.) grasp of/on (something)
  • have a clue
  • not have a clue
  • lay (one's) hands on (someone or something)
  • lay hands on
  • have a firm grip on (someone or something)