# What is −i-i exactly?

We all know that $i$ doesn’t have any sign: it is neither positive nor negative. Then how can people use $-i$ for anything?

Also, we define $i$ a number such that $i^2 = -1$. But it can also be seen that $(-i)^2 = -1$. Then in what way is $-i$ different from $i$? If it isn’t, then why do we even have something like a $-i$?

The vector $(1,-2)$ is also neither positive nor negative, yet there is value in having the operation $-(1,-2)=(-1,2)$.

Note: there is no natural meaning for “positive” for vectors, this is just an analogy.