Near Future, About to, Is to, Soon to

Question

For example if I would like to say that something will happen in the near future such as in this sentence:

• "I am about to leave" will it mean the same as "I am to leave soon" or "I am to leave?" It is unclear, because I have read that the construction of "is to do" or "is to be done" can be used to convey something happening in the near future which always is responsible by people in a way that it must have been planed by someone in order for such and such to happen as a plan for somebody else or something that is like an order. Could it be that this construction is ambiguous?

Answer 1

For your examples:

• I am about to leave
• I am to leave soon
• I am to leave

The first two are almost equivalent in meaning, whereas the last is different.

The first means that you will leave (relatively) soon, but how soon will depend on the context. In many situations (and in the usual understanding), it would mean within a short period of time.

The last example is different - it can mean that you are required to leave, or that you will leave eventually. For instance:

• I am to leave (when I have completed my work)
• I am to leave (as I have been asked to exit)

Also, the last two seem stilted and unidiomatic, unnatural, at least, in my dialect (AusE).

Answer 2

I am about to leave.

implies that you intend to leave soon.

I am to leave.

expresses an intention as well but it does not necessarily imply it is to happen in the near future unless specified with a time expression (soon, in a minute,etc.). And it does not necessarily imply that the decision has been taken by somebody else.

Examples in context.

A- Can you give a hand to move that table over there?
B- Ok, but straight away because I'm about to leave.

A- Still working at that place?
B- Well, I 'm to leave but I told them I'd wait until they've found me a replacement.