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

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

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, of, on, solid, sound
Farlex Dictionary of Idioms.

*(solid) grasp of something

 and *(sound) grasp of something; *(good) grasp of something
Fig. a firm understanding of something. (*Typically: get ~; have ~; give someone ~.) Try to get a grasp of the basic rules. You don't have a good grasp of the principles yet. John was unable to get a solid grasp of the methods used in his work, and we had to let him go.
See also: grasp, of
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • grasp
  • grasp of
  • have a (good/solid/sound/etc.) grasp of/on (something)
  • have a grasp of
  • get a (good/solid/sound/etc.) grasp of/on (something)
  • not have a clue
  • have a clue
  • lay (one's) hands on (someone or something)
  • lay hands on
  • have a firm grip on (someone or something)