What it means
わけではない is used to deny or correct an interpretation of the preceding statement. It means that something is not necessarily the case, rather than simply stating the direct opposite. It often responds to an assumption or limits the scope of what is true. The familiar form ends in わけではない, while the polite form ends in わけではありません.
Usage note
With nouns and na-adjectives, な comes before わけではない or わけではありません. Do not normally translate this form as a simple direct negative, because it usually carries a corrective or partial-denial nuance.
How to use it
私は医者なわけではありません。
It is not that I am a doctor.
この町は静かなわけではありません。
It is not that this town is quiet.
この問題は難しいわけではありません。
It is not that this problem is difficult.
彼が来るわけではありません。
It is not that he is coming.
私は医者なわけではない。
It is not that I am a doctor.
この町は静かなわけではない。
It is not that this town is quiet.
この問題は難しいわけではない。
It is not that this problem is difficult.
彼が来るわけではない。
It is not that he is coming.