You have to drop the <em>o </em>and add the appropriate ending the picture will help you . Ar turns to <em>e </em>, er or ir use <em>a</em>
Answer:
1. estaba
2. hablaba
3. pudimos (i think)
4. eran
5. se conozcan
Explanation:
abre la puerta
is the most informal
Guatemala I am super sure of it