Is this the correct way of saying this sentence?

Great, 10 days before my project is to be handed in, my printer has decided to break down / break.

"break down" and "break" are both acceptable, but personally I would tend to use "break" in this case. "break down" is often used of vehicles.

Thanks

Why do we use "is" here?

Dni483Why do we use "is" here?

Because you need a finite verb in the clause.

Great, 10 days before my project is due to be handed in , my printer has decided to break.

You can alternatively use a prepositional phrase rather than a clause.
Great, 10 days before my project's due date, my printer has deci

How about that:

Great, 10 days before my project is to be handed in, my printer decided to break.

Thanks in advance

Dni483Great, 10 days before my project is to be handed in, my printer decided to break.

Good.

If you are speaking at the very moment that your printer died, then this is more natural.
Great! It's 10 days before my project is to be handed in, and my printer has decided to break.

If you are telling the story the next day (or

Don't we use has been when we don't know exactly when the event happened?

Here we are saying that it's now 10 days before so will it be a problem without has been ?

Dni483Don't we use has been when we don't know exactly when the event happened? Here we are saying that it's now 10 days before so will it be a problem without has been ?

I'm confused. "Has been" is not in the sentence.

And how about:

Great, my project is supposed to be handed in 10 days and my printer has broken ?

I meant has decided sorry

Great, my project is supposed to be handed in in 10 days and my printer has broken.

"Hand in" a phrasal verb
"in 10 days" a prepositional phrase.