Learn Danish: Kender du svaret? — Nej, det gør jeg ikke. - Do you know the answer?

In Danish, there are two common words for "to know". Kender means to be familiar with a person, place, or a specific noun. Ved means to know a fact or a piece of information. Because svaret (the answer) is a noun here, you use kender. If you were instead saying "I know what the answer is", you would use ved.

Why is there an "-et" at the end of svaret?

Danish attaches the word for "the" directly to the end of the noun. The basic neuter word is et svar (an answer). To say "the answer", you move that et to the end of the word as a suffix, making it svaret.

In the reply, why do we say det gør jeg ikke instead of just jeg kender ikke?

This is how Danish handles short replies like "I do" or "I don't". Instead of leaving the main verb hanging or repeating it, Danish replaces it with gør (do) and uses det (it/that) to stand in for the whole action of knowing the answer. Literally, you are saying "that do I not".

Why is the word order det gør jeg ikke instead of jeg gør det ikke?

This happens because of the Danish "V2 rule", which says the verb must be the second main piece of information in a sentence. Because the reply starts with det (that) to connect back to the question, the verb gør (do) has to come immediately next in the second position. This pushes the subject jeg (I) into the third position.