Sometimes we need to make a complete negation. For this, we have “根本…不/没”. 根本 + negative words such as 不, 没, etc = not…at all
根本 + negative words such as 不/没 = not…at all
尽管我们是朋友，他表现得好像根本不认识我。Even though we were friends, he acted like he didn’t know me at all.
人家怎么看她，她根本不在乎。She doesn’t care at all what men think of her.
当然，单色地图根本不可能采用颜色的变化。
In monochrome maps, of course, colour variation cannot be employed at all.
窗户太小，根本不可能有充足的光线。
The windows are so small as not to admit much light at all.
这可是他根本没料想到的一大让步。This was an amount of compliance which he had not at all expected.
他考试及格实在是侥幸, 因为他根本没下过功夫。Passing the exam was a real fluke because he didn’t work for it at all.
你的货卖的不是地方，这里根本没人要棉织品。
You’ve brought your pigs to the wrong market this time. There’s no demand at all for cotton fabrics.
吉米采用篡改帐目的方法，去年一年根本没交任何公司税。By cooking his books Jim didn’t pay any corporation tax at all last year.
See the meaning of “根本”