What is 'では‘ and how is it used?


I've been going on a Japanese course and I don't understand the grammar behind
'dewa'. I've seen it being used in 私はおちゃとこひがすきではありません and 私はにほんじんではありません and I
don't completely understand its use in grammar and definition. Is it the
negative desu?




You are correct that ではありません is the negative form of です. At this stage I think
you should just understand it as a single unit rather than looking at では and
ありません separately. But [See this
link](https://japanese.stackexchange.com/questions/23542/%E3%81%A7%E3%81%82%E3%82%8A%E3%81%BE%E3%81%9B%E3%82%93%E3%81%A7%E3%81%AA%E3%81%84vs-%E3%81%A7%E3%81%AF%E3%81%82%E3%82%8A%E3%81%BE%E3%81%9B%E3%82%93%E3%81%A7%E3%81%AF%E3%81%AA%E3%81%84vs%E3%81%A7%E3%82%82%E3%81%82%E3%82%8A%E3%81%BE%E3%81%9B%E3%82%93%E3%81%A7%E3%82%82%E3%81%AA%E3%81%84).

You will also see じゃありません (じゃ is a contraction of では) and じゃない (ない is the
informal form of ありません) with decreasing levels of formality.

Note that it can be used to negate nouns and na-adjectives (as in your two
examples), but **not** i-adjectives and verbs.




You are correct that ではありません is the negative form of です. At this stage I think
you should just understand it as a single unit rather than looking at では and
ありません separately. But [See this
link](https://japanese.stackexchange.com/questions/23542/%E3%81%A7%E3%81%82%E3%82%8A%E3%81%BE%E3%81%9B%E3%82%93%E3%81%A7%E3%81%AA%E3%81%84vs-%E3%81%A7%E3%81%AF%E3%81%82%E3%82%8A%E3%81%BE%E3%81%9B%E3%82%93%E3%81%A7%E3%81%AF%E3%81%AA%E3%81%84vs%E3%81%A7%E3%82%82%E3%81%82%E3%82%8A%E3%81%BE%E3%81%9B%E3%82%93%E3%81%A7%E3%82%82%E3%81%AA%E3%81%84).

You will also see じゃありません (じゃ is a contraction of では) and じゃない (ない is the
informal form of ありません) with decreasing levels of formality.

Note that it can be used to negate nouns and na-adjectives (as in your two
examples), but **not** i-adjectives and verbs.

