I can't figure out how to resize Text Fields

In the GUI Editor, I try to resize Text Fields, and I cannot do it. I've tried to click and drag with all mouse buttons (left, middle, and right), including all combinations of shift, ctrl, alt, and tab with those buttons, and no matter how hard I try I cannot resize the Text Fields. I would also like to know what other things can be resized (checkboxes, buttons, etc.) if there are any. I'm not even entirely sure you can resize Text Fields...

Thanks for the help!