has to be ing

[Untaught88]

Hi,

Does this structure "has/have to be -ing" exist?

 

[jutfrank]

I would say no, it doesn't really exist as a single structure.

That is, I think it's better to understand it as two distinct structures, although they can be combined.

1) have/has to (verb)
2) be (verb-ing)

 

[Phaedrus]

Here's one fairly formulaic use that comes to mind:

"I have to be going now."

Compare:

"I have to be on my way."

 

[Untaught88]

What does "The children have to be doing their homework..." mean?

 

[probus]

Have to is the same as must.

The time at which they must remains unspecified in your fragment.

 

[Tdol]

It means that the speaker expects them to have started doing their homework by the time specified. Piscean's example has a time phrase, which makes the sentence work. Without it, it doesn't mean much.