probability - Expected value of different types of sample means

Assuming $X_i$ is iid normally distributed with $N(\mu , \sigma ^2)$

In summation notation, what is the difference between

1) $E(\overline X ^2 )$ and

2)$E(\mathrm{X}^\overline2)$
(should have the bar over the entire $X^2$)

3)$E(\overline X)^2$

so basically the difference between the expected value of the sample mean squared (1), the expected value of the RV squared's sample mean (2)(not sure how to put #2 into words sorry), and the square of the expected value of the sample mean (3).

I know

(2) $E(\mathrm{X}^\overline2)$ = $(\frac{1}{n}$)$(\sum_{i=1}^{n} X_i^2)$

(3) $E(\overline X)^2$ = $(\frac{1}{n^2}$)$(\sum_{i=1}^{n} X_i)^2$

But I'm confused on what (1) would be? How is it different from (3)?