It is often hard to know what the origin is of a Chinese character just by looking at its shape, especially is this the case with simplified characters, and when talking about radicals things get even more abstract.
Which is a pity, because understanding why characters took on their present shape can help you to remember them better, besides telling them apart from others that look somewhat similar.
Take 阝 for example, a radical that appears in hundreds of char-acters. As you may know, when placed at the left of another component it means ‘mound’ or ‘wall’. But what is its origin? Leon Wieger, in his monumental ‘Chinese Characters’, wrote that in its oldest form it looked something like represented here at the right.
As Wieger explains, the three circles on top represent a forest, which is placed on top of a declivity, consisting of the well-known 厂, which here stands for ‘slope’, and three horizontal lines which represent levels in the declivity. A later form in the development of the character is represented below it.
Finally, when used in printed material, it was written 阜, which you won’t see much in an everyday Chinese newspaper, but, as said earlier, in its radical form it is very common, so you may want to remember its origin.
These and many other etymologies of well-known Chinese characters can be found in the Chinese Character Dictionary, of which I have uploaded an update last month. You can find a brief introduction at: