convert m4v movie file to mp4

You can use the free download, Handbrake, to convert M4v to Mp4.

You can get Handbrake here:

https://handbrake.fr/

Adjust the Handbrake settings to render H.264, Mp4/AAC. However, a simple way to do it is to open Handbrake and do a File/Open Source. Navigate to your video and choose it as the source from the resulting screen. Then do File/Start Encoding. Wait a couple of minutes for the conversion to complete. Then save and import the converted clip into iMovie.

If you want to fiddle with the Handbrake settings you can set resolution and constant frame rate versus variable frame rate.

-- Rich

Glad to help, Lorra,

You know, M4v is almost identical to Mp4. For all practical purposes they are the same. M4v is an Apple format so may not be quite as universally compatible as Mp4.

-- Rich