The term tweening is derived from "in betweening,” the traditional animation term used to describe this process. Tweening significantly reduces the time required to create animation effects such as fading in or fading out, or moving an element across a frame. You can edit tweened frames individually after you create them.
You use the Tween command to automatically add or modify a series of frames between two existing frames—varying the layer properties (position, opacity, or effect parameters) evenly between the new frames to create the appearance of movement. For example, if you want to fade out a layer, set the opacity of the layer in the starting frame to 100%; then set the opacity of the same layer in the ending frame to 0%. When you tween between the two frames, the opacity of the layer is reduced evenly across the new frames.
Using tweening to animate text position
(Photoshop Extended) Make sure the Animation palette is in frame animation mode.
To apply tweening to a specific layer, select it in the Layers palette.
Select a single frame or multiple contiguous frames.
If you select a single frame, you choose whether to tween the frame with the previous frame or the next frame.
If you select two contiguous frames, new frames are added between the frames.
If you select more than two frames, existing frames between the first and last selected frames are altered by the tweening operation.
If you select the first and last frames in an animation, these frames are treated as contiguous, and tweened frames are added after the last frame. (This tweening method is useful when the animation is set to loop multiple times.)
Do one of the following:
Click the Tween button in the Animation palette.
Select Tween from the Animation palette menu.
Specify the layer or layers to be varied in the added frames:
Varies all layers in the selected frame or frames.
Varies only the currently selected layer in the selected frame or frames.
Specify layer properties to be varied:
Varies the position of the layer’s content in the new frames evenly between the beginning and ending frames.
Varies the opacity of the new frames evenly between the beginning and ending frames.
Varies the parameter settings of layer effects evenly between the beginning and ending frames.
If you selected a single frame in step 2, choose where to add frames from the Tween With menu:
Adds frames between the selected frame and the following frame. This option is not available when you select the last frame in the Animation palette.
Adds frames between the last frame and first frame. This option is available only if you select the last frame in the Animation palette.
Adds frames between the selected frame and the preceding frame. This option is not available when you select the first frame in the Animation palette.
Adds frames between the first frame and last frame. This option is available only if you select the first frame in the Animation palette.
Enter a value, or use the Up or Down Arrow key to choose the number of frames to add. (This option is not available if you selected more than two frames.)
This doesnt help. i am loikong for HOW to tween, not what it does. i right click, tween motion and nothing happens. i am an advanced flash user and not so stupid as to forgetting to add a keyframe and moving the position of my object for the tween