In this image there are strong parallel lines receding from near to far. There's a blemish in the middle of the image which can be fixed using the Perspective Clone tool.
Download this image.
1) First, duplicate the background layer. You'll have new layer named "Background Copy".
2) In the Tools palette, click on the Perspective Clone tool icon.
From the tool options, choose Modify Perspective as the Mode.
Then click anywhere in the image to show the tool.
3) By grabbing the corners, drag the perspective lines to match those in the image, as shown here.
4) Next, in the tool options for the Perspective Clone tool, change the Mode to Perspective Clone. Be certain the source is set to Image. Select a brush large enough to cover the area you are going to fix.
5) Set the clone source by Control-clicking on the "Background Copy" layer.
6) Create a new layer named "Clone" with the Layer Fill Type set to Transparency.
7) Be sure the "Clone" layer is the active layer. Click near the center of the area you want to cover. Don't worry if the cloned image is not quite lined up the way it should be.
8) Select the Move tool set to Affect: Layer and adjust the "Clone" layer to the desired position.
9) That looks better, but the cloned area obviously doesn't blend too well. I just used the Brightness & Contrast tool to make a quick adjustment to the brightness to get a better overall match. There are better ways to do this, but they're outside the scope of this example.
10) Finally, in the Layers palette, right-click on the "Clone" layer and merge it with the layer below.
This has been a very rudimentary example of using the Perspective Clone tool. To get a really good result, you would need to experiment and make some variations. Still, I hope you found it useful.