[hela]

Dear teachers,

What are the different uses / meanings of "BE TO" in the present and past?
Are my interpretations correct?

1) I am to tidy up my room before my mother gets back.
= I will have to do it (obligation given my an external authority)

2) I were to tidy up my room before my mother got back.
= I had to do it (but the interlocutor doesn't know if the speaker did tidy up his room or not)

3) I were to have tidied up my room before my mother got back.
= I had to do it but I didn't.

Thank you in advance,
Hela