ではありません

ではありません is the negative of です: "am not", "is not", "are not". Put it where です would be, after a noun or a な-adjective, and leave the remaining words as they are. The は in it is read wa.

It gives the no answer when someone asks what a person or thing is.

じゃありません

In speech では shortens to じゃ. ではありません is what you write and what you say on formal occasions. じゃありません is what you mostly hear in conversation, and it is still polite. じゃないです is a step more relaxed again.

Common mistake

ではありません does not go after an い-adjective or a verb. Each has a negative of its own: the adjective's い becomes くない, and the verb's ます becomes ません.

• × 高いではありません → 高くないです
• × 行きますではありません → 行きません

な-adjectives

A な-adjective is negated the same way as a noun.

Past

Add でした for "was not".

Usage notes

These go beyond the polite form.

Plain form

In plain speech the same negative is ではない, or じゃない in conversation.