More Past Tense (더라고, 더니) | Live Class Abridged

This live class covered two intermediate forms 더라고(요), and 더니. It also covered the similar form 더라, and a few other small related topics.

Which of these forms do you think is more difficult to use? How do you feel about using them?

Feel free to practice making your own sentences with these two forms here in the comments, or on the YouTube video.