Sure! Here are the completed sentences along with explanations:

1. The movie was very bad. I couldn't see it.
- The movie was not worth watching.

**Explanation:** The original sentence indicates that the movie was not good enough for the speaker to want to see it. The phrase "not worth watching" conveys the same meaning, emphasizing that the quality of the movie was low, leading the speaker to avoid watching it.

2. "Shut the door but don't lock it," he said to us.
- He told us to shut the door but not to lock it.

**Explanation:** The original sentence conveys a directive from a speaker to a group, indicating that they should close the door while refraining from locking it. The rephrased sentence maintains the same instruction and makes it explicit that the request is directed at "us," keeping the original intent intact.