iMovie expand the timeline to better edit?

Can someone please tell me how you expand the video in the timeline area so I can add some text through various frames throughout?

I record one long video and simply am trying to edit it and add some "Title" text at various points throughout. But when I drag and drop the single video into the timeline, it's super small and really hard to edit 4-6 second titles.

Can you expand this in the timeline section so it gives you more of a frame by frame ability? Please see screen capture.