Question

why can you not find the sqaure root of a negative number

Answer 1

Because when you solvefor a square root, its like asking "what number, when multiplied by itself, gets me _____"
So if you have the square root of a negative like sqrt(-4), you are askign yourself, what number, when multiplied by itself, gets -4?

Well, how can you ever multiply a number by itself and get a negative?

Two positives multiply to a positive and two negatives multiply to a positive. You cant have two of the same number multiply to get a negative.

Answer 2

because you did not study complex numbers yet