Yeah. It's getting annoying that the rules that the app sets up to follow drastically are suddenly dropped

But it stated 'the' what suggest using この、その、あの

There doesn't seem to be a big difference in meaning. Maybe くありません is a bit more formal. I too thought that くないです is more common, at least in spoken Japanese. Google it, lots of discussions out there... :)

What do you mean? The formal negation of an い-adjective uses the くありません form.

As far as I understand, 怖くないです is less formal, while 怖くありません is more polite. But they mean the same thing.

It's just a negative form of こわ.い Drop the い and add くありません. Thus, it doesn't have anything to do with the dog.

The formal negation of an い-adjective uses the くありません form.

Maybe this is more like "there is no fear" rather than "there is no scary dog"?

Yes i thinkmy Japanese teacher told me this as well

犬がこわがっている

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