Correct way to ask the carrier when your package will be shipped

Question

Is it correct to say "Do you know when the package is expected to be shipped?"? What about When is the expected date for the package to be shipped? Are there other ways to say this?

What is "is+past tense" (is expected) called?

Answer 1

Do you know when the package is expected to be shipped?

When is the expected date for the package to be shipped?

Both of these are acceptable. The term you're looking for, I think, is passive voice since "is expected" and "to be shipped" are in the passive form of the verbs "to expect" and "to ship":

They expect that I will ship the package

It is expected (by them) that the package will be shipped (by me)

To answer your question about other ways to say this, the passive form of the verb sounds somewhat more polite than the active form. If you don't care about politeness, you can use the active voice:

Do you know when you expect to ship the package?

What is the expected date you will ship the package?

or even more direct:

When are you going to ship the package?

There are, of course, many other verbs you can use to express the same concept:

When do you plan to mail me the package?

When do you think you will deliver the package?

When do you anticipate the package will arrive?

And so on.

Final note: In your second sentence "expected" is not the past tense of "to expect". It's the adjective form of "expect" that modifies the noun "date": "the expected date"