"It is hardly a spider!"

Translation: Det är knappast en spindel!

[Sarah.K.Ha]

What is the meaning of this? Is it as if to say, that spider is so small or so unspiderlike it's barely a spider? As if you made a cake and it turned out poorly, someone might say "that is hardly a cake!"

[Arnauti]

I take it to mean 'I think it's really unlikely that that thing is a spider'.

[Zmrzlina]

It means the former.

http://en.wiktionary.org/wiki/knappast

[EmilieFF]

Why is it "det" and not "den"?

[Arnauti]

We always use det when we start talking about some new subject that wasn't mentioned before.
Much longer post about this here: https://www.duolingo.com/comment/9708920

[Crystal289612]

It can be both:)

[Arnauti]

Without context, it needs to be det.

[AHS-9]

I tried "Det är knappt en spindel" but it was rejected. Of these two terms (knappast knappt), can only knappast be used to indicate probability?

[Arnauti]

Yes. knappt is used to mean 'slightly less than' or 'barely', 'not quite', 'just under', 'not more than'.

Both work in a sentence like Det tror jag knappast/knappt 'I hardly believe it' though. (much like you can say I can hardly/barely believe it in English)