the act of rubbing your skin with your nails

There are lots of hand movements and scratching of chins.

Keep your fingernails short to avoid skin damage from any unconscious scratching. 留短指甲以避免在不自觉抓挠时损伤皮肤。

the sound of something such as an animal's sharp nails rubbing on a surface

Then I heard it again - the sound of scratching behind the wall.

The scratching of his pen was the only sound. 唯一的声音是他的笔的刮擦声。

They were soft scratchings or shufflings, like the sounds made by an animal as it sniffed about in search of food.

cuts on or damage to a surface caused by something hard or rough rubbing on it

Metal utensils will cause some scratching of the surface of your non-stick cookware. 金属餐具会在不粘锅的表面上造成一些划痕。

writing cut into the surface of something

In the abandoned school there were hundreds of scratchings carved into wooden desktops. 在那所废弃的学校里，木质课桌上有数百个刻痕。

These characters were more like the ancient scratchings on Chinese oracle bones than their complicated modern Chinese counterparts.