When learning Japanese the most disliked part could be memorizing kanji, especially if you have reached a higher level (like preparing for JLPT N2 or N1). Perhaps, if you look at kanji from a different perspective you will feel that it is the most interesting part of the language.
Kanji can be classified into different categories. They can be grouped according to meaning or use, stroke, radical, pronunciation or type. These kind of segregations or associations are not only interesting but also intensify the ability to remember kanji.
Kanji are grouped according to meaning or use in the following way,
一 二 三 四 五 六 七 八 九 十
頭 顔 目 手 足 etc.
A stroke or 画 (kaku) is the smallest component of a kanji. In order to find out a kanji from a dictionary’s 画数 list (kakusu list), it is very important to know the number of strokes in a kanji.
二画(nikaku) 二、人、力 etc.
There are kanji with up to 23 stroke counts (in the previous joyo kanji list), but there are other kanji whose stroke count goes way much higher.
Kanji are also grouped according to the radicals or 部首 (bushu). Radicals form a noticeably meaningful part of a kanji. For example, the following kanji can be categorized under the radical 糸 or ito hen,
紀(era/period) 練(practice) 緑(green) 約(promise)
All the above kanji have one part in common i.e. the radical 糸 (ito, thread). 糸 is the smallest meaningful component in the above kanji. Since radicals are parts of a kanji, they are also formed by combining strokes.
A kanji has two separate pronunciations, 音読み (onyomi, chinese reading) and 訓読み (kunyomi, Japanese reading). Sometimes a kanji has only On reading but no Kun reading. Quite a few kanji have more than one On reading. This is because a same kanji was introduced to Japan from China in different eras or from different regions of China, with different pronunciations.
the kanji for span/space is 間 aida (Kun reading) kan,ken (On reading)
When the kanji 間 is used alone (without another kanji) Kun reading is used. When used with another kanji or many kanji to form a separate word (Jukugo or compound word), like 時間 (jikan, time) or 人間 (ningen, human), the On reading is used. 間 官 漢 簡 are read as ‘kan’ according to the On reading. Hence, all these kanji can be grouped together according to their On readings.
The main six types of kanji are
象形文字, Shoukei moji or pictographs. As the name suggests, these kanji were simply derived from the drawings of objects of nature. For example,
指示文字, Shiji moji or signs. These kanji indicate concepts like time, location or number etc. For example,
上 下 一 二
会意文字, Kaii moji or ideographs. These are compound kanji formed with more than one shoukei or shiji moji kanji (including radicals).
形成文字, Kesei moji or phonetic ideographs kanji are also compound kanji like the Kaii moji kanji, but the difference lies in the fact that one of the kanji components indicate the pronunciation and another component indicates the meaning of the kanji. These are the most common kanji of all, in other words greater in number (in the jouyou list) than the rest of the types.
糸＋己＝ 紀 (ki, era/period)
言＋己＝ 記 (ki, chronicles)
(thread+self= chronicles) where 己 is the component (on the right) which denotes the pronunciation of 紀. 言 and 糸 are the components (on the left) which denotes the character.
転注文字, Tenchuu moji are those kanji whose meaning or pronunciation was changed from its original Chinese meaning or pronunciation. For example,
楽 (raku) mean comfort but its also pronounced as gaku and used in the word 音楽 (ongaku) which means music.
仮借文字, Kasha moji are referred to those kanji which are mainly used to denote sounds rather than meaning. These mainly appear in the names of countries, for example 米 in 米国(America) . Kasha moji kanji are less common in Japanese than Chinese, because Japanese generally uses Katakana to write names of foreign countries.