"ka wahine, nā wāhine"
Translation:the woman, the women
This is a good question. Most words don't change in spelling or pronunciation when made plural. It just so happens that wāhine (and some other words like it) are exceptions to the rule. We have already seen wahine -> wāhine. A couple more examples are kaikamahine -> kaikamāhine and makua -> mākua. Definitely check out the Tips & Notes section (the lightbulb button that appears when you click on a skill, on the web only, unfortunately) for more grammar-related info.
Why is there a line over the a in the plural of woman, but not a line over the a in the singular?
The line that appears over some letters in Hawaiian words is called a kahakō (or macron). Wahine just so happens to be one of the special words that gets a kahakō over one of its vowels when plural. So, wahine -> wāhine. Most words stay the same in spelling whether used in a singular or plural way, but there are a few others that have the same behavior as wahine, such as kaikamahine -> kaikamāhine and makua -> mākua.