"The spider builds a home for six days."
Translation:거미가 엿새 동안 집을 지어요.
You mean the English? Normally it doesn't. In speaking, the point you are stressing is done by voice, but it writing it definitely should come last. The point you are making is the number of days it takes.
You could say, "The spider, for six days, builds a home." You need the commas because you are separating the verb from its subject. Then you are stressing that the home is being built.
You could say, "For six days, the spider builds a home." The comma is because you are displacing the subject from the start. This is more that the home is being built by the spider.
You could even say "The spider builds, for six days, a home." This would stress that it is a home. The comma because you are separating the verb from its object. The most natural order in English, though, is subject verb object complement, though as you can see the complement is more free to float.
As for Korean or Japanese, they tend to put what is stressed first, so IMHO directly translated it would be "Builds a home for six days, does the spider." Duo is a bit funny about putting the subject, or agent here, first. It has to cater to English speakers, after all.