iMovie help

select the point of the video that you want to insert the clip , and goto edit and split video
type your text and make sure that the over black is unclicked
drag the effect title ie ZOOM over to your cut in your movie

it will render the clip

job done

 

The first point that liketom is making is the most important. In iMovie, you can only add a title at the start of a clip, hence having to split the clip if you want to have the title appear a few seconds into a sequence.

Choose the type of type you want, type in what you want it to say, play around with the length you want it on the screen and preview it if you like. Then drag the name of the type effect (so music video, credits) to your movie's timeline.