The negative form of a Japanese noun is made by adding では (ga) + ない (nai).
In English, you can form a negative noun sentence by placing isn't, am not, or aren't in front of the noun (e.g., a pen). * isn't (is not) + a pen

Now that you have learned questions and negative sentences, you can have basic conversations.
A : Is this a pen?
B : No! This is not a pen.

How is it?
Simple, right?
They are similar to each other.