Îi aștept la ușă.

Because Romanian a aștepta normally takes a direct object.

So English I wait for them becomes Romanian Îi aștept, literally more like I await them.

• I wait for them → Îi aștept
• not aștept pentru ei in this meaning

This is one of the most common differences English speakers notice with this verb.

Here, îi means them as a direct object pronoun placed before the verb.

So:

• îi = them
• aștept = I wait / I am waiting

Together: Îi aștept = I’m waiting for them

In this sentence, îi usually refers to a masculine plural or mixed-gender plural group.

Good question — îi can represent different pronouns in different contexts.

Here it means them because a aștepta takes a direct object, not an indirect object.

Compare:

• Îi dau cartea. = I give him/her the book.
  Here îi is indirect object: to him/her

• Îi aștept. = I’m waiting for them.
  Here îi is direct object: them

So the verb and sentence structure tell you how to understand îi.

Because Romanian unstressed object pronouns usually go before the conjugated verb.

So Romanian says:

• Îi aștept = I wait for them

not usually:

• Aștept îi

This is normal Romanian word order for clitic pronouns.

Yes. Aștept is the 1st person singular present form of a aștepta.

That means the subject I is already built into the verb:

• aștept = I wait / I am waiting

Because of that, Romanian usually does not need eu unless you want emphasis:

• Eu îi aștept la ușă. = I’m the one waiting for them at the door.

It can be either, depending on context.

Romanian present tense often covers both:

• I wait for them
• I am waiting for them

So Îi aștept la ușă can mean either a general present or a present-in-progress meaning.

Here la ușă means at the door or by the door.

The preposition la can mean different things depending on context, including:

• at
• to
• by

In this sentence it expresses location, not motion.

So:

• Îi aștept la ușă = I’m waiting for them at the door

Because Romanian and English use articles differently.

Romanian often says la + noun without the definite article in common location expressions, where English prefers the:

• la ușă = at the door
• la masă = at the table
• la școală = at school

So even though ușă by itself looks like a door, the whole phrase la ușă naturally means at the door in context.

Not when you are using only the clitic pronoun îi.

So this is correct:

• Îi aștept la ușă.

If you add a full noun referring to people, pe is normally used:

• Îi aștept pe copii la ușă. = I’m waiting for the children at the door.

If you use a stressed pronoun, you also normally get pe:

• Îi aștept pe ei la ușă.

So in your sentence, pe is not needed because îi already does the job.

The object pronoun changes.

Some useful comparisons:

• Îl aștept la ușă. = I’m waiting for him at the door.
• O aștept la ușă. = I’m waiting for her at the door.
• Îi aștept la ușă. = I’m waiting for them at the door.
  usually masculine plural or mixed group
• Le aștept la ușă. = I’m waiting for them at the door.
  feminine plural

So îi here is specifically not the form for her or him.

Yes, but the neutral, everyday order is:

• Îi aștept la ușă.

You could also say:

• La ușă îi aștept.

That puts more focus on la ușă. It might sound like:

• It’s at the door that I’m waiting for them

Romanian word order is somewhat flexible, but the original sentence is the most straightforward version.

A simple approximation is:

uhy ash-TEPT la OO-shuh

A bit more exactly:

• Îi ≈ a quick sound like ɨj
• aștept = ash-TEPT
• ușă = OO-shuh

Notes:

• î is a Romanian vowel that English does not really have
• ș sounds like English sh
• ă is a short unstressed vowel, like a very reduced uh

So the whole sentence is roughly:

uhy ash-TEPT la OO-shuh