I use to be able to change the speed of my animations by going at the end of the motion, clicking the double arrow and dragging it. The double arrow no longer shows up. What now shows up is an arrow connected with a square and when I try to drag it, it only copies the animation. It doesn't slow it down. Please help 

Click the Speed icon in the Timeline.
Then, when the cursor hovers over the last frame of the motion, you will see the double arrow sign. 
Drag the motion clip.


YouTube Tutorials Here