The real part of the complex number $-8i$ is 0, because there is no real component in this purely imaginary number.

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Here are 5 related questions:

1. What is the imaginary part of $-8i$?
2. How do you add two complex numbers?
3. How do you find the modulus of a complex number like $-8i$?
4. What is the argument of the complex number $-8i$?
5. How do you multiply complex numbers?

Tip: The real part of a complex number is the coefficient of the real component, while the imaginary part is the coefficient of $i$.