@DICK-NICHOLS Sure you can. Assuming you're using MEP: just find the image on your computer using the media pool on the Import tab (upper right window), then drag it onto a timeline track BELOW the video object. For example, if your video and audio is on track 1 and 2, place the image on track 3. Remember MEP looks up from the bottom to the top when creating the video. This will mean that your image will sit "on top" of the video. Sounds weird, but it's logical when you think about it.
Your image will probably be completely covering your background video at this point. Do this:
Place the Play marker over your image then click on the image;
In the Effects menu, click on Size and Position.
Orange Drag handles will appear on the corners: simply drag your image to resize it and position it ass you desire.