It is not because things are difficult that we do not dare; it is because we do not dare that things are difficult.
Seneca

When the th and d are very close together, the tip of your tongue must move quickly from touching the teeth to touching the gum ridge so that both sounds can be distinctly heard.

1. Don’t do that Dan.
2. What does that thing do?
3. Did they breathe in the dust?
4. Dan thought it was dad’s birthday.
5. How dare they do that!
6. They did it the other day. Didn’t they?