What is the radical for the word "learn"?

Son.

I. A radical is a part of a compound character that is obtained by dividing it. In the past, the left side of a compound character was called "bias" and the right side was "side"; now the components of a compound character are collectively called "bias". Located on the left side of the word, called "left side"; located on the right side of the word, called "right side".

What is the difference between a Chinese character's radicals, radicals, combinations of strokes and roots?

The radicals are defined from the perspective of character formation. It is customary to say "left and right side". This is the result of a structural analysis of Chinese characters using the "dichotomy" method. Due to the complexity of the structure of Chinese characters, many Chinese characters do not have a left-right structure. Therefore, there is no longer any distinction between left and right, and all characters are called "偏旁".

The radicals are defined from the point of view of application function. When Xu Shen wrote the Shuowen Jiezi, he arranged the Chinese characters according to their form and meaning. He arranged the characters containing the same ideograms together, and called this method of arranging the characters "Separate Partial Dwelling". The first character of each "part" is the "radical". It can be seen that radicals are also partials, which are special "partials" used as the basis for arranging and retrieving Chinese characters. The radical is always the side of a character, but the side of a character is not always the radical. For example, "丁" (ding) and "亢" (hyper) are radicals, but not radicals.

The root of a character is the result of analyzing the form of a character from the point of view of the smallest discrete structural unit of the character. The radicals of modern Chinese characters are different from the radicals and radicals derived from traditional structural analysis of Chinese characters. There are many radicals that include more than two roots. For example, the roots of "样" are "木, 羊"; the roots of "暺" are "忄, 斤, 欠"; the roots of "颉" are "士, 口, 页"; and the roots of "韶" are "立, 曰, 刀, 口".

The concepts of "dichotomy" and "radicals" in traditional philology cannot meet the needs of modern practice of Chinese character structure analysis. This is because:① The radical is not the smallest discrete unit in the structure of a Chinese character. There are many Chinese characters whose "radicals" themselves include several discrete components, such as "赢", "幂", "谬", "隋", "蒯", "剜", "撅", "阔", "胸", and so on. ② Some of the radicals are a composite character, which can be continued to be split. Word and oblique boundaries are not clear, the lack of a clear logical relationship. For example: He - Jia, Bei/Li, Mouth, Bei; Zhang - Yin, Ten / Zhang - Li, Early / Li, Day, Ten; Shao - Yin, Call / Li, Day, Knife, Mouth; Widow - Female, Frost / Female, Rain, Wood, Eye; ③ Radicals are still in use, but the principles and criteria for determining the radicals have been changed from the principle of "meaning class" to the principle of "checking methodology. The structural analysis method of "Stroke - Stroke Combination - Character Root - Chinese Character" is conducive to the teaching and application of Chinese characters, especially to the application of computerized Chinese character recognition and synthesis technology[2]?

The most fundamental point is that the scope of radicals is much larger than that of radicals. In other words, what is a radical must be a radical, but what is a radical is not necessarily a radical.