Connecting adjectives, "does not have to A and B"

Question

The simplest things seem to be the hardest.

I am exercising the "does not have to be" structure.

If I want to say "the book does not have to be expensive", it is (may be?):

本は高くなくてもいいです。

But how do I say "the book does not have to be expensive and big"?

I asked this in chat and got a kind answer from Xeo.

Xeo, thank you for your help and I hope I may quote you here:

@saidy afaik, you generally connect adjectives with the て-form. So I'd wager it works here, too: 「本は高くなくて大きくなくてもいいです。」

I may be totally wrong, though. Better wait until one of the gurus answer this :)

Is this the correct way to connect adjectives in this case?

Thank you for reading this far. Any help is appreciated.

Answer 1

No, the answer you got in chat is not quite right.

「[本]{ほん}は[高]{たか}くなくて[大]{おお}きくなくてもいいです。」

You would need to use 「も」 twice to make it grammatical. You could say:

「本は高くなくても、大きくなくてもいいです。」

The sentence is grammatical now, but it just does not sound very natural. As a Japanese-speaker, I could not imagine someone saying this sentence in real life. If it were a catch copy in advertisement (perhaps for e-books), it would sound pretty natural.

You could also say something like:

「本は高い[必要]{ひつよう}もなければ、大きい必要もありません。」

Either way, you would need to use 「も」 twice. It is as though you would need to use "n" twice in saying "neither A nor B".