Can I cut the clip in the middle iMovie?

Yes, you can cut footage from the middle of your movie.

To delete a clip, select it and press Delete on your keyboard.

You can also drag its edge to trim off the part of the clip that you don't want to display in your movie.

You can also place the playhead at a place where you want to split the clip and do a Modify/Split Clip at the in-point and then move the playhead to the outpoint and do another Modify/Split slip. Then you can select and delete (by pressing Delete on your keyboard) the segment that you created.

Another way is to drag the cursor over the clip while holding down ther r key, to create a yellow box that outlines the portion that you want to delete. Then delete the portion in the yellow box by pressing delete on your keyboard.

Be aware that deleting a clip to which an audio clip is coupled will also delete the audio clip. To avoid that, put your cursor on the audio clip and, while pressing down, drag the audio clip down to a lower audio well until you see the little coupling handle pull off of the video clip.

The deleting that you do will not remove the deleted portion from the iMovie library. It will just remove it from the project timeline so that it is no longer in the project. You can always drag the clip back in from the media browser. Likewise, any trimmed footage can be restored by simply dragging the edge of the clip back out.

-- Rich