Contradiction: Forms Of Ja Nai

1)Ja nai(じゃない)

It means not. It is used to make negative sentences. It is usually used by female.

Here’s some example:

genki janai =not cheerful, not energetic, not healthy

Noun, pronoun+じゃない(= janai)

kore janai =not this

Past tense: 〜じゃなかった (= ~ janakatta)

Genki janakatta=not cheerful, energetic, health

じゃない(= janai)in a negative sentence.

Maggie wa neko janai. = Maggie is not a cat.

Inu janai yo = It's not a dog.

Yo is like a verbal exclamation point, it just adds emphasis to the statement.

2)Ja nai desu (じゃないです。)

Janai desuis the negative form ofdesu. It is little more polite than janai. Desuhas affirmative and negative forms, as well the non-past and past forms.

Kore wa keitai janai desu. = This is not a mobile phone.

Susan-san wa sensei janai desu. = Susan-san is not a teacher.

Be careful.You can’t make a negative form ofi-adjectivewithではない(= dewa nai) andじゃない (= janai).

Wrong!かわいいじゃない (= kawaii janai) →かわいくない(= kawaikunai)

Wrong!動くじゃない (= ugoku janai) →動かない(= ugokanai)

3)Dewa arimasen(じゃありません)

It is more polite form of janai. While talking to your elder or your boss Dewa arimasen should be used. Ja arimasen is also used in place of Dewa arimasen.

“Ja” is just a contraction of “Dewa.”

Watashi wa koukousei ja arimasen. = I am not a high school student.

Sore wa isudewa arimasen. = It'snota chair.

COMPARING:

There is no difference in the meaning. Only difference is the degree of politeness. The decreasing degree of formality goes like this: じゃありません (ja arimasen) じゃないです (ja nai desu) じゃない (ja nai).

Maggie wa neko de wa arimasen. ->

Maggi wa neko janai desu. ->Maggie is not a cat.

Maggie wa neko janai. ->

All mean the same.

This is just an overveiw of the basic form.