他对英语语法有很好的理解。

He has a good ___grasp of English grammar.

要在职业上取得进步，对关键软件工具的扎实理解是必不可少的。

To progress in your career, a solid ___grasp of key software tools is essential.

她对复杂理论的深刻理解使她成为一位受尊敬的学者。

Her profound ___grasp of complex theories made her a respected scholar.