Mystery solved about Japanese adjectives!

You might not believe this, but even though I’ve been fluent in Japanese for over 30 years and wrote five Japanese textbooks, it wasn’t until I learned Korean, that I understood why Japanese had two types of adjectives. Each with different rules for conjugation. For reference I will summarize what is taught in Japanese From Zero! books.

There are THREE adjective types in Japanese:

1. い adjectives (i)

These ALWAYS end with a hiragana い and they can be used DIRECTLY in front of a word to modify.

2. な adjectives (na)

These can end in with practically any hiragana character. But for them to be able to modify something they require な which is where they get their name from:

How these adjectives types are conjugated into negative form, past tense form etc. is different depending on the type. And the reality is that if you’ve studied Japanese on http://fromzero.com or with the Japanese From Zero! books you will learn all about these adjective types, but you won’t learn WHY they exist.

It wasn’t until I was sitting in a Korean class in Korea when I noticed that Korean also had two adjective types. Once I heard what they were called I immediately knew why Japanese has い (i) and な (na) adjective types. In Korean they differentiate the types by calling them “Native Korean adjectives” and “Sino-Korean adjectives”.

Sino-Korean means “Chinese Korean” in case you didn’t know what “Sino” meant. I know I didn’t at first.

So, Japanese な adjectives are Chinese origin, and Japanese い adjectives are native Japanese.

This means that when Chinese characters were introduced to Japan and Korea, Chinese adjectives were added and classified differently than the ones that already existed. Sometimes there are two adjectives that mean the same thing, but one is originally Japanese and one came from the Chinese infusion. The native Japanese い adjective word for “kind” is やさしい (yasashii) but there is also a Chinese な adjective that means the same thing しんせつ (shinsetsu).

Now, to make it even more interesting, let’s talk about non-Chinese adjectives added to Japanese. Nowadays if Japan is going to add anything to Japanese the new words mostly come from English due to a strong relationship with Japan and English speaking countries. And it turns out that all new adjectives added from English are also な adjectives. For example:

So if you ever learn a new adjective that’s written in katakana (which is primarily used for foreign origin words) or written only in kanji with no hiragana い at the end, then it’s automatically a な (na) adjective. Keep in mind that just because an adjective ends in い (i) doesn’t automatically make it an い adjective. For example, 綺麗 (きれい) (kirei), which means “pretty”, ends in an い, but it’s normally written with two kanji and no hiragana い (i) at the end. This is a な (na) adjective so for a “pretty person” you would say, きれいな ひと (kirei na hito).

And finally, for very observant people, you might have noticed that I mentioned there were three Japanese adjective types, but only talked about two.

In the Japanese From Zero! book series we call the third type simply の (no) adjective because it requires a の when directly modifying. In reality it’s just a noun being turned into an adjective. For example:

3. の adjectives (no)

These are nouns changed into adjectives by adding の (no).

In the end, I think what surprises me the most is that it took me learning Korean to learn about this fundamental part of Japanese. Wait until you see what I learned about Korean once I started learning Chinese. We’ll save that for another time.