"BE TO" to express necessity

[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

[Temico]

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
I believe that there is something wrong with the use of "were" in your sentences.
For example;
A: What were you doing on Monday afternoon?
B: I was fishing in the lake.

A: What were to do before your mother got back?
B: I was to tidy up my room before my mother got back.

A: What were to have done before your mother got back?
B: I was to have tidied up my room before my mother got back.

Compare:
i) If I were to tidy up my room before my mother got back, she would let me go out with my friends.
ii) If I were to have tidied up my room before my mother got back, I wouldn't have been scolded by her.

[Rusty]

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
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)
(OK. Or, I am supposed to/expected to/ tidy up my room...).

2) I were was 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) (Your interpretation is fine. Use the simple past verb, was.
Use I were when there is an if-clause. Example:
If I were to tidy up my room (now), my mother would be happy (later). Whether or not the speaker will really tidy up the room is uncertain).

3) I were was to have tidied up my room before my mother got back.
= I had to do it but I didn't. (Right).
If I were to have tidied up my room (past), my mother would have been happy. (At a time later than the tidy-up).

[hela]

Dear Temico and Rusty,

Sorry, I've made a mistake. It should be "I was", of course. This done, could you please tell me if the difference in meaning between my sentences #2 & 3 are correct? Would you have more examples for me, please?

Kind regards,
Hela

[Temico]

Dear Temico and Rusty,

Sorry, I've made a mistake. It should be "I was", of course. This done, could you please tell me if the difference in meaning between my sentences #2 & 3 are correct? Would you have more examples for me, please?

Kind regards,
Hela

A: What were to do before your mother got back?
B: I was to tidy up my room before my mother got back.(supposed to tidy...)

A: What were to have done before your mother got back?
B: I was to have tidied up my room before my mother got back.(supposed to but didn't....)