Question on Japanese grammar.?

Question

When learning the "i" adjectives and "na" adjectives, how do you know which ending the word will have? Do you just have to memorize which category the adjective falls into or is there some trick to know the answer?

Answer 1

If you look at the how it is written (in Japanese), this often shows you which it is:

Utsukushii and Kirei both end in "i", but "kirei" is a "na" adjective. Here is what makes them different:

美しい　(utsukushii) - beautiful - this character ends in "i" and the character い at the end is a good indicator that it is an "i" adjective. When it is conjugated, the い (i) is dropped and replaced by the conjugation.

Example: 美しくないです。　(utsukushikunai desu) It's not beautiful. Notice how the い (i) character was dropped and replaced by くない (kunai) to modify it and make it negative.

綺麗 (kirei) - pretty - the romaji ends in "i", but look at the kanji. There is no way to modify this, because if you change the kanji, you change the meaning. Kirei is a "na" adjective.

"na" adjectives are treated like nouns, so "It's not pretty", it would be 綺麗じゃないです。　（kirei ja nai desu)


Knowing that, you will then know how to use them as adjectives:
美しい女です。(utsukushii onna desu) - (She's) a beautiful woman.
綺麗な女です。(kirei na onna desu.) - (She's) a pretty woman.

Answer 2

It's pretty simple really. Generally speaking if the word ends in an "i", it's an i-adjective, otherwise it's a na-adjective.
There are some exceptions, such as when the "i" is part of the kanji, as in "元気" (genki) or　"本気" (honki). Once you start learning kanji it'll become clear.
As a side note, there is one modern exception: Even though 綺麗 (kirei) falls under the same rule as genki, Japanese treat it as an i-adjective; so they say "kirekunai" instead of "kirei ja nai"

Answer 3

i adjectives are like oishii ,furui ,atarashii ,the adjectives always end with i.when we have i adjectives we just add it directly to the noun.

however adjectives that do not have 'i' behind r known as na adjectives and when we add it to a noun,we have to use adjectives +na +nouns.there is special case for the word kirei tho it ends with i ,it is a na adjectives and we say kirei na hito desu

hahaha no need to memorise just remember whenever see the adjectives and if there is any i or no i ending.that is how u differentiate it.