grasp
n. countablen. a firm hold on something with your hand, or a clear understanding of a difficult idea. If you have a good grasp of a subject, you know it well.
n. a firm physical grip or hold; figuratively, a comprehensive understanding or mental mastery of a concept or subject.
She has a good grasp of basic mathematics.
After three months of intensive study, the student finally gained a solid grasp of the local language.
The candidate's firm grasp of international trade policy distinguished her from the other applicants during the televised debate, where she explained complex tariffs with remarkable clarity.
From Middle English graspen, grapsen, craspen (“to grope; feel around”), from Old English grǣpsian, from Proto-West Germanic graipisōn, from Proto-Germanic graipisōną, from Proto-Indo-European gʰrebʰ- (“to take, seize, rake”), the same ultimate source as grab. Cognate with Saterland Frisian grapsje (“to grab, grasp”), German Low German grapsen (“to grab; grasp”), German grapsen and grapschen, Old English grāpian ("to touch, feel, grasp"; > Modern English grope). Compare also Swedish krafsa (“to scatch; scabble”), Norwegian krafse (“to scramble”).
Often used with the preposition 'of' when referring to understanding ('a grasp of physics').
She has a good grasp in EnglishShe has a good grasp of EnglishWhen referring to understanding or knowledge, the noun 'grasp' is followed by the preposition 'of', not 'in'.